http://WWW.sabi.co.UK/ Notes mostly about Linux and computer issues en-GB http://blogs.law.Harvard.edu/tech/rss/ notes {at} notes.for.sabi.co.UK Copyright 2006 P. Grandi 14000 AMD Intel Microsoft Nintendo Sony CPU OS VoIP file sytem free software hardware performance system administration videogames virtual memory ALSA Debian Fedora GNU JFS KDE Linux MS Windows 2000 MS Windows XP MS Windows PS/3 RedHat SUSE UNIX XFS Xbox 360 ext3 Mon, 22 Jan 2007 21:05:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070122 Spotted impressively high prices for ordinary computer cables. Online too. cables shopping http://www.sabi.co.uk/blog/0701jan.html#070120b Mon, 22 Jan 2007 21:00:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070120b A few environment variables can be a nice orthogonal base for configuration space, especially shell-script configuration files. UNIX Linux system administration shell http://www.sabi.co.uk/blog/0701jan.html#070120b Sat, 20 Jan 2007 23:15:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070120 Amazing performance of FireWire 800, where the same disk runs 2-3 times as fast with it than with FireWire 400 or USB2, and at speeds near those of SATA. storage hardware USB2 SATA USB2 IEEE1394 FireWire http://www.sabi.co.uk/blog/0701jan.html#070120 Sat, 20 Jan 2007 09:55:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070115 I have just tried two branded external USB2 hard drives, and they seem to work fine, and fairly quickly, and without the power supply issues that come from underspecified power bricks. But eSATA is going to be hopefully much better. storage hardware USB2 SATA USB2 IEEE1394 FireWire http://www.sabi.co.uk/blog/0701jan.html#070115 Mon, 15 Jan 2007 22:25:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070108 SiCortex has launched massively parallel low power systems based in 6-CPU MIPS chips based on the idea that low power is good and memory stalls are bad. architecture hardware parallel CPU http://www.sabi.co.uk/blog/0701jan.html#070108 Mon, 08 Jan 2007 22:10:00 +0000 http://WWW.sabi.co.UK/blog/0701jan.html#070105 The DNS is a hierarchical linearized scheme for naming interfaces, not computers or other nodes. But people don't think in terms of interfaces, and nodes with multiple interfaces on multiple subnets pose some naming issues. Some alternatives are briefly discussed. networking sysadm Internet DNS naming http://www.sabi.co.uk/blog/0701jan.html#070105 Fri, 05 Jan 2007 21:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061231 Putting in per-node caching or proxy servers is a form of non-transparent static interposition, a technique which in its general form is rarely available but results in great flexibility. It is related to advising and 'become:' in programming languages, and to DNS service discovery standards. networking languages sysadm DNS http://www.sabi.co.uk/Notes/anno06-4th.html#061231 Sun, 31 Dec 2006 23:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061230b Using YumEx and Yum to set up a laptop with a lot of tools, and suffering because of their slowness and limitations. Things could be better than this... RedHat Fedora performance Linux http://www.sabi.co.uk/Notes/anno06-4th.html#061230b Sat, 30 Dec 2006 20:10:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061230 Some simple speed tests show that current top end CPUs and system can transmit at full speed on 1gb/s wires even without jumbo frames as they can sustain amazingly high interrupt and context switch rates, and intelligent network adapters help. networking performance Linux http://www.sabi.co.uk/Notes/anno06-4th.html#061230 Sat, 30 Dec 2006 11:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061227 Smalltalk-72, Smalltalk-76, the big difference between message passing and overloading why it matters, and many CPUs on the same chip. programming software engineering object oriented overloading message passing http://www.sabi.co.uk/Notes/anno06-4th.html#061227 Wed, 27 Dec 2006 15:10:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061226b It is often useful to run caching or slave servers on all clients so that most server addresses can be configured as 127.0.0.1 as reconfiguring and restarting servers is often a lot quicker and less painful than reconfiguring and restarting applications. sysadm servers networking Internet Ethernet http://www.sabi.co.uk/Notes/anno06-4th.html#061226b Tue, 26 Dec 2006 21:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061226 Centralized vs. localized service depends on a table of service vs. level of redundancy. Partitioning it into subtables and then reading it by rows or columns gives different service structures. Many services have dependencies, therefore it is pointless to have independent redundancy for them. In general the idea of bringing servers nearer to the point of delivery, usually a workgroup, is indeed reasonable according to some plausible criteria. sysadm servers networking Internet Ethernet http://www.sabi.co.uk/Notes/anno06-4th.html#061226 Tue, 26 Dec 2006 14:40:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061224 Smalltalk-72, Smalltalk-76, the big difference between message passing and overloading, and terminology confusion. programming software engineering object oriented overloading message passing http://www.sabi.co.uk/Notes/anno06-4th.html#061224 Sun, 24 Dec 2006 13:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061223 What are overloading and genericity and their relationship to OO. programming software engineering object oriented modules overloading genericity http://www.sabi.co.uk/Notes/anno06-4th.html#061223 Sat, 23 Dec 2006 18:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061216 Tomcat has a slightly odd way of resolving request URLs into servlets. Binding different ports on the same domain to different default servlets requires a somewhat unusual configuration, but it is useful for one-to-one URL forwarding from an Apache front-end via AJP. sysadm Linux Apache Tomcat web http://www.sabi.co.uk/Notes/anno06-4th.html#061216 Sat, 16 Dec 2006 20:35:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061212 More details about VLANs: bridged VLANs are often partitioned by VLAN tagging, two opposite but complementary techniques. These are often used together in large networks, which mostly means inter-site and even international ones, both to take advantage of large broadcast domains and mitigate their effects, especially when servers and services are centralized. networking sysadm Linux NFS VLAN Ethernet http://www.sabi.co.uk/Notes/anno06-4th.html#061212 Tue, 12 Dec 2006 21:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061210b Some application problems are explained by pointing out that while TCP transport is reliable, signaling is not, and anyhow TCP under Linux has a very long and excessive timeout for detecting a dead connection. networking Internet TCP NFS Linux http://www.sabi.co.uk/Notes/anno06-4th.html#061210b Sun, 10 Dec 2006 19:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061210 Large network infrastructures based on bridging and central servers are often the result of hasty attempts to scale up smaller infrastructures. They may seem to work, but I think that they are fragile and inefficient. I reckon that workgroup servers and local services are preferable. Difficult choices anyhow about home directories and laptops. networking sysadm Linux NFS VLAN Ethernet http://www.sabi.co.uk/Notes/anno06-4th.html#061210 Sun, 10 Dec 2006 17:35:00 +0000 http://WWW.sabi.co.UK/#sourcesSabishape?061126 While the logic of my traffic shaping setup script has not changed much, this update contains many adjustments to details that should improve it a fair bit. Linux networking Netfilter iptables shell shaping IP configuration traffic control Sun, 26 Nov 2006 15:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061111 An article reports that after a rather short time of being connected to the Internet and browsing an unprotected installation of MS Windows XP gets infected with very many trojans, spyware, ... programs. Microsoft Internet security spyware http://www.sabi.co.uk/Notes/anno06-4th.html#061111 Sat, 11 Nov 2006 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-4th.html#061105 Belated impressions from the recent Linux World Expo in London. Linux IBM RedHat Novell system administration network administration http://www.sabi.co.uk/Notes/anno06-4th.html#061105 Sun, 05 Nov 2006 22:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103f A study (from an interested party) reports very, very high rates of spyware and trojan infections. Owning someone else's computer can be quite profitable. security MS Windows privacy http://www.sabi.co.uk/Notes/anno06-4th.html#061103f Fri, 03 Nov 2006 22:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103e Just discovered a standard to run the FireWire bus protocol over 1000gb/s Ethernet wiring. Quite an interesting combination. cabling FireWire Ethernet http://www.sabi.co.uk/Notes/anno06-4th.html#061103e Fri, 03 Nov 2006 21:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103d A pundit points out that outsourcing often results in high incentives to stagnation for the outsourcing supplier. sociology business outsourcing http://www.sabi.co.uk/Notes/anno06-4th.html#061103d Fri, 03 Nov 2006 21:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103c An article reports amazing numbers of lost laptops, of which few are reclaimed, because managers prefer to get a new new than wasting time in recovering the old one. security sociology http://www.sabi.co.uk/Notes/anno06-4th.html#061103c Fri, 03 Nov 2006 21:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103b Some connector designs are ptrone to breaking off, and this is bad particularly for sockets. FireWire connectors were designed well though. design quality mechanical connector http://www.sabi.co.uk/Notes/anno06-4th.html#061103b Fri, 03 Nov 2006 21:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061103 A pundit points out that CSS is a very dense and compact languages, and mishaps like poor implementation have wide effects. web CSS HTML http://www.sabi.co.uk/Notes/anno06-4th.html#061103 Fri, 03 Nov 2006 21:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061101 Some small attributes of digital cameras are actually quite relevant, like having an external flash socket. photography digital camera http://www.sabi.co.uk/Notes/anno06-4th.html#061101 Wed, 01 Nov 2006 21:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061031b Just found out that often EMC2, a noted storage system manufacturer, defaults to RAID3 or a variant. RAID storage http://www.sabi.co.uk/Notes/anno06-4th.html#061031b Tue, 31 Oct 2006 21:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061031 Commenting on a discussion about the difference between the two levels of storage protocols (link and command) and why bother with SANs as NAS is possible. NAS SAN SCSI ATA http://www.sabi.co.uk/Notes/anno06-4th.html#061031 Tue, 31 Oct 2006 20:15:00 +0100 http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#teknikPosture?061022 Using a "kneeling chair" to site somewhat high while not putting weight on the thighs. hardware seating ergonomics Sun, 22 Oct 2006 18:40:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFS.html?061022 Some updates to the bibliography section and the links section of my file system for Linux notes. Linux RAID XFS JFS file system Sun, 22 Oct 2006 17:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061022b A list of quotes showing that some people misuse RAID5 as in 15+1 disc drive configurations, or worse. Linux RAID XFS file system http://www.sabi.co.uk/Notes/anno06-4th.html#061022b Sun, 22 Oct 2006 17:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061022 A pointer to and some comments on a very interesting paper showing some large recent improvements in XFS performance on a parallel system with multiple concurrent reads and writes. Some surprising comparisons with JFS and other file systems. Linux XFS JFS file system http://www.sabi.co.uk/Notes/anno06-4th.html#061022 Sun, 22 Oct 2006 16:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061015 I have recently had a look and upgraded a bit a small video-on-demand system that I first set-up about 10 years ago. Amusing to see how hardware had evolved in the meantime, and why I chose certain components may be interesting. architecture hardware video movies SCSI network http://www.sabi.co.uk/Notes/anno06-4th.html#061015 Sun, 15 Oct 2006 11:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061014 Some more experiments with multiple concurrent stream reading from a disc. Turns out that the 'anticipatory' elevator in Linux maintains aggregate bandwidth by sorting and batching requests, a bit cruder but overall with the same results as tagged queueing. architecture hardware video movies SCSI network http://www.sabi.co.uk/Notes/anno06-4th.html#061014 Sat, 14 Oct 2006 08:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061013 I have recently had a look and upgraded a bit a small video-on-demand system that I first set-up about 10 years ago. Amusing to see how hardware had evolved in the meantime, and why I chose certain components may be interesting. architecture hardware video movies SCSI network http://www.sabi.co.uk/Notes/anno06-4th.html#061013 Fri, 13 Oct 2006 17:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061004 In video games HDR rendering means doing intermediate lighting calculations with higher range than that used for final output, to prevent clipping due to overflow and underflow. This could be done by more careful staging of calculations, but it also delivers higher precision, not range, which helps with multipass algorithms architecture hardware graphics videogames NVIDIA http://www.sabi.co.uk/Notes/anno06-4th.html#061004 Wed, 04 Oct 2006 19:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-4th.html#061003 Discovered High Dynamic Range photography, which is interesting but misnomed, unlike High Dynamic Range in videogames, which is truer to its name. architecture hardware graphics videogames NVIDIA http://www.sabi.co.uk/Notes/anno06-4th.html#061003 Tue, 03 Oct 2006 23:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060928c Intel has been talking about a very fast chip with 80 FPUs to be delivered in about 5 years. There is also already available the ClearSpeed CSX600 with 96 FPUs, but apparently it is much more expensive. architecture hardware CPU Intel http://www.sabi.co.uk/Notes/anno06-3rd.html#060928c Thu, 28 Sep 2006 22:35:00 +0100 http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#belkinF5D7630?060928 Updated the review of the Belkin F5D7630 with further condemnation of the poor quality of its firmware, especially after loading on it the much better firmware of the compatible SMC 7804WBRA. ADSL quality hardware networking system administration Thu, 28 Sep 2006 18:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060928b My Belkin F5D7630 ADSL modem/router has always been buggy, but I managed to work around most bugs. Being fed up with it, I loaded on it the firmware from the compatible SMC 7804WBRA and what a difference. It seems clear to me that while Belkin and SMC used the same source, SMC spent some effort in testing and fixing the firmware, and documenting it well. Makes me wish I bought the SMC model. ADSL quality hardware networking system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060928b Thu, 28 Sep 2006 18:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060928 The Linux 'automount' daemon is quite convenient but is uses a different mount map format from '/etc/fstab'. But it can get the mount map by running a program, and it is was to write a script to convert '/etc/fstab' entries into 'automount' map ones on the line, and this preserves the flexibility and maintainability of keeping all mount configuration in one place. UNIX Linux filesystems system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060928 Thu, 28 Sep 2006 18:00:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060924c Spotted a couple on entries in the PostgreSQL mailing list comparing dual core AMD verbus hyperthreading Intel CPUs for running that highly parallel DBMS. AMD dual core looks good, but surprisingly so does hyperthreading. Linux Apache AMD Athlon Opteron performance http://www.sabi.co.uk/Notes/anno06-3rd.html#060924 Sun, 24 Sep 2006 23:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060924b IBM will deliver a 32,000 CPU Linux based cluster where half of the elements will be Opteron based and half Cell based, and claim that some new software infrastructure will help manage the cluster. Linux Opteron AMD IBM Cell cluster performance http://www.sabi.co.uk/Notes/anno06-3rd.html#060924b Sun, 24 Sep 2006 22:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060924 Some recent report shows that the same large scale web benchmark on system with 2 Opteron CPUs runs noticeable faster in 32b than 64b mode for between 128 and 100 and 400 clients. Comparing with a similar report for a test for 2 Athlon MP CPUs it looks like the reason is memory: the same program compiled for 32b mode uses less memory, and memory bandwidth, than in 64b mode. Linux Apache AMD Athlon Opteron performance http://www.sabi.co.uk/Notes/anno06-3rd.html#060924 Sun, 24 Sep 2006 19:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060920b A pointer to Polipo, a nice and featureful proxy cache one might want to consider as an alternative to Apache or Squid, especially for IPv6 sites. Squid Apache programming Internet system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060920b Wed, 20 Sep 2006 23:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060920 For various reasons I am now using Apache as a proxy cache instead of Squid. This has required fixing some bugs and extending a bit the Apache caching module. Squid Apache programming Internet system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060920 Wed, 20 Sep 2006 08:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060917c According to one argument, local IPv6 addresses have the advantage of being portable. But only in the sense of always requiring NAT to a non-portable prefix. An old non-portable global prefix can also be NAT'ed to a new different non-portable global prefix. network Internet IPv6 NAT system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060917c Sun, 17 Sep 2006 23:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060917b Some network administrators would like to have something like IPv4 private addresses and NAT in IPv6; a couple of ways have been proposed to achieve something like that, but things could be simpler, understanding what is the real goal, which is not private addresses or NAT as such. network Internet IPv6 NAT security system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060917b Sun, 17 Sep 2006 18:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060917 It is somewhat amazing that some minor but annoying bugs have remained in some very popular applications for several years. I haven't fixed them myself simply to avoid maintaining my own patches, and I haven't reported them to avoid the hassle. programming KDE Emacs system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060917 Sun, 17 Sep 2006 17:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060916 Why IPv6 larger datagram sizes matter when link bandwidths are high, not just window size when latency is also high. network Internet IPv6 system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060916 Sat, 16 Sep 2006 11:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060915 The root DNS servers get thousands of queries per second about site local private address ranges. As Stonebraker learned decades ago, misconfigured servers and networks are the norm, not the exception. network Internet DNS DBMS performance system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060915 Fri, 15 Sep 2006 08:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060914b Using statistics collected from Steam users, Valve has discovered that poor game loading times depend a lot of fragmentation. Also means they scan users disks and report that back. videogames business performance file systems http://www.sabi.co.uk/Notes/anno06-3rd.html#060914b Thu, 14 Sep 2006 19:25:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060914 Valve reports that developing new episodes of an already developed game is four times cheaper. Also, that World of Warcraft is the benchmark. videogames business middleware MMORPG http://www.sabi.co.uk/Notes/anno06-3rd.html#060914 Thu, 14 Sep 2006 19:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060913b The designers of the original FireWire connectors designed them to be resistant to repeated plugging/unplugging. The number of insertion cycles for which sockets are rated is indeed in general an important and underrated topic. hardware FireWire IEEE1394 security debugging system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060913b Wed, 13 Sep 2006 20:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060913 Most FireWire host adapters offer excessive accessive access to their host's memory, and devices can initiate operations because FireWire is essentially P2P. This can be turned to advantage for debugging. hardware FireWire IEEE1394 security debugging system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060913 Wed, 13 Sep 2006 19:25:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060911 More on IPv6, the practical options to get IPv6 connectivity. network Internet IPv6 security system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060911 Mon, 11 Sep 2006 22:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060910b Found a nice paper about QoS with Linux using the LARTC framework. Interesting observations about sampling rate. But puzzling setup of an example: incoming shaping is done at the gateway egree interface, not the ingress one. Linux LARTC network Internet QoS sabishape system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060910b Sun, 10 Sep 2006 20:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060910 While chatting about network management at a large scientific site IPv6 was mentioned. I quite like it, and anyhow it is going to become indispensable soon. It also has some nice advantages by design, and some serendipitous ones. network Internet IPv6 security system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060910 Sun, 10 Sep 2006 18:05:00 +0100 http://WWW.sabi.co.UK/Notes/miscShopping.html#princesGrapefruitLarge Just discovered my local Coop has a 1.25kg can of grapefruit segments for a good price. Excellent value. shopping food http://www.sabi.co.uk/Notes/miscShopping.html#princesGrapefruitLarge Mon, 11 Sep 2006 18:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060828 The Ubuntu project is going to replace the ugly System V style 'init' with 'upstart', which will be a general process manager, replacing 'cron' and 'inetd' as well. Seems a bit of a mess to me, but let's hope it is not. UNIX Linux pragmatics system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060828 Mon, 28 Aug 2006 23:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060825 There are now motherboards with a direct HyperTransport interface called HTX, and performance seems to be much higher than PCI-E for high traffic network and probably most other coprocessors. hardware CPU AMD Intel bus http://www.sabi.co.uk/Notes/anno06-3rd.html#060825 Fri, 25 Aug 2006 22:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060822 AMD hopes for a 40% market share in servers, where it has the advantage because of HyperTransport. Intel instead dominates laptops, especially with Core 2 Duo, and low end desktops with integrated graphics. hardware CPU AMD Intel http://www.sabi.co.uk/Notes/anno06-3rd.html#060822 Tue, 22 Aug 2006 22:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060821c The x86 Linux kernel maps real memory into the address space of each process, and there is a performance advantage in the ability to map all of real memory in every process. On 32-bit CPUs the address space is limited to 4GiB, so one needs to decide how much to use to map real memory and how much for the use of each process. Linux kernel memory virtual memory http://www.sabi.co.uk/Notes/anno06-3rd.html#060821c Mon, 21 Aug 2006 23:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060821b Just seen another chip with 16 CPUs, this one not quite there yet but with the aim of having a grid style architecture. architecture hardware CPU MIPS Linux grid http://www.sabi.co.uk/Notes/anno06-3rd.html#060821b Mon, 21 Aug 2006 13:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060821 Linux was first announced 15 years ago. It is a long time, and perhaps Plan 9 or BSD should have enjoyed its popularity. But it is good enough and its licence is the GPL. Linux kernel operating system GPL BSD UNIX http://www.sabi.co.uk/Notes/anno06-3rd.html#060821 Mon, 21 Aug 2006 09:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060815 Movidis is selling a server based on a low power 16-CPU chip by Cavium. Interesting tradeoffs, looks like (and I hope it is) a winner. architecture hardware CPU MIPS Linux http://www.sabi.co.uk/Notes/anno06-3rd.html#060815 Tue, 15 Aug 2006 18:15:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFonts.html#appBlog?060813 Some updates to my fonts notes and the addition of a new section with pointers to font related entries in my blog. X Linux UNIX fonts Sun, 13 Aug 2006 21:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060810b My own conventions for tagging various parts of speech and types of discourse when I write HTML. XML HTML SGML markup http://www.sabi.co.uk/Notes/anno06-3rd.html#060810b Thu, 10 Aug 2006 22:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060810 While in general I reckon that font antialiasing is not a good idea and is unnecessary, on low DPI screen it can be the least bad of a bad lot. Also, some hints on how to scale up fonts on high DPI monitors. Linux fonts antialiasing X window system http://www.sabi.co.uk/Notes/anno06-3rd.html#060810 Thu, 10 Aug 2006 21:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060809 Microformats are an objectionable way of describing data not with XML tags, but with HTML attributes. That is not quite nice. But much of the same effect can be obtained by describing text with HTML tags, and help data processing programs with attributes. XML HTML SGML markup http://www.sabi.co.uk/Notes/anno06-3rd.html#060809 Wed, 09 Aug 2006 19:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060808 The Linux resident set size of processes, a better way to compute it, and what would be a much better way to define it. Linux operating systems paging memory management http://www.sabi.co.uk/Notes/anno06-3rd.html#060808 Tue, 08 Aug 2006 20:55:00 +0100 http://WWW.sabi.co.UK/?060807 My site front page has been restructured (the content is almost the same) to use tables instead of lists, as that seems slightly more readable. web html design Mon, 07 Aug 2006 15:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060806c The 'mlocate' version of 'updatedb' will not descend into an empty directory, and automounter mount points look like empty directories. The better solution is to change how 'updatedb' is used, to have a list of filesystems it should scan and a 'locate' database for each one (usually in each one). UNIX Linux filesystems system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060806c Sun, 06 Aug 2006 23:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060806b I am quite unhappy about the current structure of the GNU/Linux startup system, based on a misdesigned corruption of the original System V 'init' scheme. Which should be fixed, not corrupted, or replaced with something better. UNIX Linux pragmatics system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060806b Sun, 06 Aug 2006 23:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060806 Just spotted some (moderately) bad code in some kernel IDE driver. All too typical unfortunately. Linux software engineering pragmatics programming http://www.sabi.co.uk/Notes/anno06-3rd.html#060806 Sun, 06 Aug 2006 16:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060805 Static mounting via '/etc/fstab' can be replaced with dynamic mounting via 'autofs' and there are some reasonable advantages. Linux filesystems partitions system administration http://www.sabi.co.uk/Notes/anno06-3rd.html#060805 Sat, 05 Aug 2006 23:25:00 +0100 http://WWW.sabi.co.UK/#sourcesDokde?060805 My alternative (to 'startkde') KDE startup is not updated for KDE 3.5.3, which has a slightly different startup sequence. It also contains a couple of fixes to bugs in 'startkde'. Linux KDE script shell Sat, 05 Aug 2006 17:10:00 +0100 http://WWW.sabi.co.UK/Notes/miscGames.html#gameSniper?060729 Reviewed the "Sniper Elite" game and slightly edited some of the other game reviews. videogames games reviews http://WWW.sabi.co.UK/Notes/miscGames.html#gameSniper?060729 Sat, 29 Jul 2006 13:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060728b architecture system design pattern matching web services http://www.sabi.co.uk/Notes/anno06-3rd.html#060728b Fri, 28 Jul 2006 16:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060728 The 'sysfs' file system defines files that for each device state which major and minor numbers its device files should have, but does not actually define the device file itself. Linux kernel udev devfs http://www.sabi.co.uk/Notes/anno06-1st.html#060728 Fri, 28 Jul 2006 14:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060727b Comparing recent CPUs on recent games, these seem rather CPU bound. games videogames Athlon Core 2 graphics CPU NVIDIA AMD Intel http://www.sabi.co.uk/Notes/anno06-3rd.html#060727b Thu, 27 Jul 2006 23:25:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060727 Another user has sold out and discovered that desktop GNU/Linux performs a lot better with 1GiB than with 512MiB of RAM. Linux RAM ECC 1GiB swapping virtual memory KDE http://www.sabi.co.uk/Notes/anno06-1st.html#060727 Thu, 27 Jul 2006 22:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060726 Many people seem to think that in GNU/Linux command options should be last, just as in MS Windows. UNIX Linux MS Windows http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060726 Wed, 26 Jul 2006 23:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060725b The CEO of NVIDIA speaks about programmability in graphics cards, and approves the Blu-Ray drive in the PS3, and the large investments companies have to put in development with a 6 month product generation cycle. PC games graphics NVIDIA PS/3 http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060725b Tue, 25 Jul 2006 22:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060725 Some comments on the AMD and ATi merger, which seems to me a bit strange, because the two companies are really not that related. I suspect that it is mainly a reaction to Intel's dominance of the integrated chipset market. PC games graphics VGA AMD ATi http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060725 Tue, 25 Jul 2006 21:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060724d Mark Rein complains with some causes that most laptops and many desktops are sold with Intel graphics chips that cannot run the latest games, including those from his company. Too bad that game companies don't feel like selling to the majority of the market though. probably the issue is games with too much geometry, which is not as easily scalable as effects. PC games graphics VGA http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724d Mon, 24 Jul 2006 22:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060724c Controlling Linux kernel and base user level sources is precious, and some sources are merged in with a lot less fuss than others. Linux kernel udev Reiser4 XFS http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724c Mon, 24 Jul 2006 21:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060724b The GNU/Linux utility 'ms-sys -p' fixes a number of partition issues for MS Windows, but it damages NTFS filesystems. Linux partitions MS Windows NTFS http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724b Mon, 24 Jul 2006 21:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060724 Mysteriously and temporarily a hard drive shifts its contents by 16 bytes. PC IO discs peripherals http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060724 Mon, 24 Jul 2006 21:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060723 Just been told that the 'cfq' elevator under Linux can prioritize IO, which can help with interactive responsiveness. Linux IO latency performance games http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060723 Sun, 23 Jul 2006 23:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060713 After a long time, my default Linux kernel build is now for SMP and voluntary preemption, even if I have a single CPU, just to improve interactive responsiveness. I have switched because the popularity of dual core chips means that the SMP and premption code is now an itch for more people, so probably it is more reliable than in the past. Linux SMP games latency preemption performance http://WWW.sabi.co.UK/Notes/anno06-3rd.html#060713 Thu, 13 Jul 2006 20:10:00 +0100 http://WWW.sabi.co.UK/Cfg/ALSA/asound.conf?060704 Oops, just realized that the definition of the front/rear split parametric PCMs was not quite right, and cleaned it up too. Linux sound ALSA asound.conf http://www.sabi.co.uk/Cfg/ALSA/asound.conf?060704 Tue, 04 Jul 2006 22:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-3rd.html#060702 There is now a plan to add 48 bit block addresses and extents to the 'ext3' file system, and that sounds odd as there are several other existing file systems with the same or better features. But RedHat has a large interest in extending 'ext3' rather than using a new file system type for RHEL. Linux file system ext3 ext4 JFS XFS Reiser4 RedHat RHEL http://www.sabi.co.uk/Notes/anno06-3rd.html#060702 Sun, 02 Jul 2006 23:00:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFS.html#fsRefsDesc?060702 Added a couple of memos on the evolution of the 'ext3' file system into the new 'ext4' one. Linux file system ext3 ext4 RedHat http://www.sabi.co.uk/Notes/linuxFS.html#fsRefsDesc?060702 Sun, 02 Jul 2006 22:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060625b Linux allocates swap space blocks a bit too late, and this causes severe performance problems. There is a simple and general alternative. Linux virtual memory swapping paging file system http://www.sabi.co.uk/Notes/anno06-2nd.html#060625b Sun, 25 Jun 2006 22:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060625 If an interface depends on more than one implementation type C++ does not help a lot with avoiding code or API duplication, because of a specific restriction. C++ template class interface implementation object oriented http://www.sabi.co.uk/Notes/anno06-2nd.html#060625 Sun, 25 Jun 2006 21:35:00 +0100 http://WWW.sabi.co.UK/Notes/miscShopping#msBritishSausages A review of MS "british premium pork sausages", whose ingredients include 93% "pork", but have perhaps 50% content of apparently no nutritional value, and the protein content that may imply perhaps only 55% pork meat overall. shopping pork sausage http://www.sabi.co.uk/Notes/miscShopping#msBritishSausages Thu, 15 Jun 2006 23:25:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060612 The results of some tests on the sustainable uplink and downlink bandwidths for my ADSL line. ADSL bandwidth networking traffic shaping http://www.sabi.co.uk/Notes/anno06-2nd.html#060612 Mon, 12 Jun 2006 20:10:00 +0100 http://WWW.sabi.co.UK/#sourcesSabishape?060608 I have fixed a couple of small improprieties; also introduced a distinction in the traffic classes between the ceiling bandwidth (same as total for all classes) and target rate, whose sum total is now lower, not higher than the total for their parent. Linux networking Netfilter iptables shell shaping IP configuration traffic control Thu, 08 Jun 2006 18:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060606b What ''constructors'' should do in C++, what the terms ''object'', ''constructor'' and 'destructor'' mean in C++ and in computer science, and what ''destructors'' should do in C++. C++ object constructor destructor class instance object oriented http://www.sabi.co.uk/Notes/anno06-2nd.html#060606b Tue, 06 Jun 2006 23:00:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060606 Found some screenshots of the new Microsoft Vista fonts which are ClearType oriented. They are nice, but the fringing is bad and the hinting makes them look bad without antialising. Microsoft fonts ClearType antialiasing http://www.sabi.co.uk/Notes/anno06-2nd.html#060606 Tue, 06 Jun 2006 18:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060604 In review of 10 keyboards 9 had black keys with white lettering. It looks cool but with time it becomes unreadable. hardware keyboard ergonomics http://www.sabi.co.uk/Notes/anno06-2nd.html#060604 Sun, 04 Jun 2006 16:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060603 I had speculated that Sony sees a PS/3 with Linux as a PC replacement, not just a games console. Sony's head of development has confirmed this quite clearly. PS/3 Sony Microsoft marketing videogames http://www.sabi.co.uk/Notes/anno06-2nd.html#060603 Sat, 03 Jun 2006 10:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060602 How to separate interface from implementation in C++, in particular when the data representation is different, but the API is equivalent. C++ templates inheritance interface implementation http://www.sabi.co.uk/Notes/anno06-2nd.html#060602 Fri, 02 Jun 2006 23:10:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFS.html?060602 Many updates to my page of notes on Linux file systems, mostly copied from the tech blog with some updates. Linux file system ext3 JFS XFS ReiserFS http://www.sabi.co.uk/Notes/linuxFS.html?060602 Fri, 02 Jun 2006 19:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060528 Some more illustration of what coarse parallelism in games could be like, for example for characters. videogames Sony PS3 parallelism Cell http://www.sabi.co.uk/Notes/anno06-2nd.html#060528 Sun, 28 May 2006 22:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060524 During a discussion of non-virtual destructors in C++, someone suggested that they can be used to indicate a class should not be derived for. Possibly, but it goes against the grain... C++ virtual Java final http://www.sabi.co.uk/Notes/anno06-2nd.html#060524 Wed, 24 May 2006 23:40:00 +0100 http://WWW.sabi.co.UK/Notes/linuxKDE.html?060515 Some revision and extension of my KDE notes, in particular added details on how to do some particular tasks. KDE hints X Linux performance http://www.sabi.co.uk/Notes/linuxKDE.html?060515 Mon, 15 May 2006 18:00:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060514 A quick write speed test of CIFS and NFS, Linux-to-Linux over a 100MHz network. Unexpectedly writing lots of small files is slower with CIFS than NFS in asynchronous mode. Either CIFS does not run in asynchronous mode or perhaps lots more system calls is the problem. Linux file system SMB NFS CIFS Samba Ethernet http://www.sabi.co.uk/Notes/anno06-2nd.html#060514 Sun, 14 May 2006 19:25:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060513 A quick read speed test of CIFS and NFS, Linux-to-Linux over a 100MHz network. As expected usually CIFS is preferable. Linux file system SMB NFS CIFS Samba Ethernet http://www.sabi.co.uk/Notes/anno06-2nd.html#060513 Sat, 13 May 2006 20:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060512c A reminder of what OO is about and why it works. it is a program decomposition paradigm where each programming software engineering object oriented modules overloading genericity http://www.sabi.co.uk/Notes/anno06-2nd.html#060512c Fri, 12 May 2006 20:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060512b Many important optimisations like inlining should apply not to the definition of functions or classes, but to their instantiations. programming software engineering optimization inlining generics overloading templates inheritance http://www.sabi.co.uk/Notes/anno06-2nd.html#060512b Fri, 12 May 2006 19:00:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060512 Type systems can be open, closed or manifest, and code can belong to programs or libraries. programming type systems software engineering optimization C C++ http://www.sabi.co.uk/Notes/anno06-2nd.html#060512 Fri, 12 May 2006 18:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060511 Some comments on the importance of Gran Turismo as a Playstation signature game, and coarse parallelism, relating to reports of an incomplete demo of the PS3 demo for the game. videogames Sony PS3 parallelism Cell http://www.sabi.co.uk/Notes/anno06-2nd.html#060511 Thu, 11 May 2006 09:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060510 A quick speed test of Reiser4, with JFS as a reference point, on my root filesystem. Looks good, but seems to delay writing out modified inodes for a long time. Linux file system JFS Reiser4 performance http://www.sabi.co.uk/Notes/anno06-2nd.html#060510 Wed, 10 May 2006 13:55:00 +0100 http://WWW.sabi.co.UK/Notes/miscShopping.html#primarkClothes?060509 Primark sells basic clothes that are cheap and of reasonable quality. Shopping clothes polo shirts underwear Primark http://www.sabi.co.uk/Notes/miscShopping.html#primarkClothes?060509 Tue, 09 May 2006 17:45:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060509 A simpler summary of what to do to have nice fonts with GNU/Linux, at least in X. Linux X11 fonts FreeType Type 1 TrueType http://WWW.sabi.co.UK/Notes/anno06-2nd.html#060509 Tue, 09 May 2006 16:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060507 Accidentally obtained a second IT8212F based ATA host adapter, and this one actually works fairly well. Linux kernel driver ATA SCSI RAID http://WWW.sabi.co.UK/Notes/anno06-2nd.html#060507 Sun, 05 May 2006 19:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060505b Usually it is believed that there only be one SSL enabled web site per IP address, but there are at least two important and useful special cases where there can be multiple ones. encryption SSL HTTP web Apache SSL OpenSSL web server virtual hosts http://www.sabi.co.uk/Notes/anno06-1st.html#060505b Fri, 05 May 2006 22:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060505 Comments on two interesting papers on the space costs of delayed reference counting, and the time cost of tracing and delayed deallocation in garbage collection. garbage collection reference counting memory memory management http://www.sabi.co.uk/Notes/anno06-1st.html#060505 Fri, 05 May 2006 21:05:00 +0100 http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#zalmanFanmate2?060505 A positive review of the Zalman Fanmate2 fan RPM adjuster. It does not become hot. hardware cooling noise http://www.sabi.co.uk/Notes/hwNotesReviews.html#zalmanFanmate2?060505 Fri, 05 May 2006 16:35:00 +0100 http://WWW.sabi.co.UK/blog/anno06-1st.html#060504 Thanks to a convenient Zalman Fanmate2 I have reduced the speed of both my PCU and rear case fans to the point I can't hear them anymore, and without much if any increase in temperatures. hardware cooling noise Athlon http://www.sabi.co.uk/Notes/anno06-1st.html#060504 Thu, 04 May 2006 20:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-1st.html#060502c Halo for is a lot faster on my new CPU than the slower one. Clearly CPU bound. Was this intentional? videogames performance http://www.sabi.co.uk/Notes/anno06-1st.html#060502c Tue, 02 May 2006 23:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060502b Updates the the Linux ALSA sound notes and sample ALSA lib configurations. Linux sound ALSA http://www.sabi.co.uk/Notes/anno06-2nd.html#060502b Tue, 02 May 2006 18:20:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060502 Linux X11 fonts FontConfig http://WWW.sabi.co.UK/Notes/anno06-2nd.html#060502 Tue, 02 May 2006 15:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060430 Linux X11 fonts FontConfig http://WWW.sabi.co.UK/Notes/anno06-2nd.html#060430 Sun, 30 Apr 2006 22:40:00 +0100 http://WWW.sabi.co.UK/Cfg/ALSA/asound.conf?060430 There was a bizarre but fatal problem in my parametric 'asound.conf' in the 'pcm.rec'/'dsnoop' configuration. It is fixed now. Also, small updates and cleanups. Linux sound ALSA asound.conf http://www.sabi.co.uk/Cfg/ALSA/asound.conf?060430 Sun, 30 Apr 2006 22:10:00 +0100 http://WWW.sabi.co.UK/Cfg/X11/?060430 Added DejaVu aliases. Linux X11 fonts http://WWW.sabi.co.UK/Cfg/X11/?060420 Sun, 30 Apr 2006 21:30:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060429 The Linux fonts mess: what are the best options for rasterization quality? Options and comparisons. Linux fonts TrueType Type1 X11 FontConfig http://www.sabi.co.uk/Notes/anno06-2nd.html#060429 Sat, 29 Apr 2006 20:05:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060424c The UNIX style of pragmatics is ever more forgotten... When did the fade begin? I suspect that was with SystemIII and 'fsck'. Linux UNIX pragmatics style http://www.sabi.co.uk/Notes/anno06-2nd.html#060424c Mon, 24 Apr 2006 23:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060424b Gathering some 'fsck' times for two rather different filesystems, and observations: time mostly proportional to number of inodes, can be pretty long for large filesystems, even in the best case. Linux file system ext3 JFS XFS ReiserFS fsck performance http://www.sabi.co.uk/Notes/anno06-2nd.html#060424b Mon, 24 Apr 2006 23:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060424 Some speed tests on a filesystem with 65GiB and 85k files in it, under 'ext3', JFS, XFS, ReiserFS. Linux ext3 file system JFS XFS ReiserFS performance http://www.sabi.co.uk/Notes/anno06-2nd.html#060424 Mon, 24 Apr 2006 23:10:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060423 I have been sad to read a series of quotes bashing Microsoft when they both are instead healthy self criticism and they bash technical and project management issues that are problems with free software too. Free software is about freedom. GNU microsoft free software opensource http://www.sabi.co.uk/Notes/anno06-2nd.html#060423 Sun, 23 Apr 2006 19:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060422b Defragmentation is often best done by disc-to-disc backup (image) and restore (tree). But then backup should be done that way too. Linux backup performance fragmentation http://www.sabi.co.uk/Notes/anno06-2nd.html#060422b Sat, 22 Apr 2006 23:50:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060422 Some comments on what seems to me a rather flawed and incomplete speed test of a few file systems. Still a lot better than the previous one I had seen. Linux file system JFS XFS ReiserFS ext3 performance fragmentation http://www.sabi.co.uk/Notes/anno06-2nd.html#060422 Sat, 22 Apr 2006 13:15:00 +0100 http://WWW.sabi.co.UK/Notes/linuxFonts.html?060420 Updates to my Linux font notes, with some extensions. Linux fonts TrueType Type1 X windows http://www.sabi.co.uk/Notes/linuxFonts.html?060420 Thu, 20 Apr 2006 21:20:00 +0100 http://WWW.sabi.co.UK/Notes/linuxPragmaCoding.html#pathsDir Added to the Linux coding pragmatics recommendations to open files, especially configuration files, following a directory path, and what the default path should look like. UNIX Linux programming pragmatics http://www.sabi.co.uk/Notes/hwNotesReviews.html#pathsDir Thu, 20 Apr 2006 14:00:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060419 GameSpy have a page with usage statistics for many popular non-MMORPG online games. Well, they aren't so popular compared to MMORPGs, except for CounterStrike. games MMORPG http://www.sabi.co.uk/Notes/anno06-2nd.html#060419 Wed, 19 Apr 2006 23:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060418 I have recently bought a new USB2/FW PCI card, and somewhat earlier a new 3.5" external USB2/FW enclosure, so I now have two of each; so i tested the various combinations for compatibility and speed. The results are as usual a bit depressing. Linux hardware USB2 IEEE1394 http://www.sabi.co.uk/Notes/anno06-2nd.html#060418 Tue, 18 Apr 2006 21:15:00 +0100 http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#nonameULT31311 Review of an ULT31311 external USB2/FW box for 3.5" drives. It has some significant issues, and overall I can tolerate it, but I wish I had bought another one. hardware USB2 IEEE1394 http://www.sabi.co.uk/Notes/hwNotesReviews.html#nonameULT31311 Tue, 18 Apr 2006 20:05:00 +0100 http://WWW.sabi.co.UK/Notes/hwNotesReviews.html#nonameTT346U2F Review of a TT-346U2F external USB2/FW box for 5.25" and 3.5" drives. It has some issues, but I like it. hardware USB2 IEEE1394 http://www.sabi.co.uk/Notes/hwNotesReviews.html#nonameTT346U2F Tue, 18 Apr 2006 19:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060416b Solid is the new KDE hardware abstraction layer, and is build on top of various other already hairy layers. Not the UNIX way, more like the Microsoft/Debian way. Linux hardware autoconfiguration http://www.sabi.co.uk/Notes/anno06-2nd.html#060416b Sun, 16 Apr 2006 20:40:00 +0100 http://WWW.sabi.co.UK/blog/anno06-2nd.html#060416 More testing of JFS performance drop over time as files get rewritten, this time after a full upgrade from Fedora 4 to Fedora 5. JFS file system Linux performance fragmentation http://www.sabi.co.uk/Notes/anno06-2nd.html#060416 Sun, 16 Apr 2006 14:15:00 +0100 http://WWW.sabi.co.UK/blog/anno06-1st.html#060327 The script that start 'xfs' in Fedora 5 overwrites font configuration files, and wrongly too. Fedora autoconfiguration fonts http://www.sabi.co.uk/Notes/anno06-1st.html#060327 Thu, 27 Mar 2006 20:15:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060326 Upgrading my CPU and motherboard to significantly faster ones results in massive improvement to the speed of reading from hard drives under Linux, it looks like IO under Linux is CPU bound, amazingly. Linux IO Athlon 64 speed http://www.sabi.co.uk/Notes/anno06-1st.html#060326 Wed, 26 Mar 2006 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060325 After several months of using Fedora 4 I have upgraded to Fedora 5. Overall I am satisfied, even if I have disabled some of the more deleterious hacks. Linux Fedora http://www.sabi.co.uk/Notes/anno06-1st.html#060325 Tue, 25 Mar 2006 21:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060323 Just discovered that someone has found why modified file pages can take a long time to be written back to disc under Linux, irrespetive of the relevant kernel parameters, and has produced a very useful patch. Linux IO buffering hard disc http://www.sabi.co.uk/Notes/anno06-1st.html#060323 Thu, 23 Mar 2006 19:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060322 A test of recent PC games as to when they become CPU bound. The outcome is that a fast CPU is a good idea... videogames http://www.sabi.co.uk/Notes/anno06-1st.html#060322 Wed, 22 Mar 2006 23:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060320 The Financial Times writes about the impending release of the Godfather videogame, whose delayed release cost EA US$800m in its market value. videogames http://www.sabi.co.uk/Notes/anno06-1st.html#060320 Mon, 20 Mar 2006 16:30:00 +0000 http://WWW.sabi.co.UK/#sourcesSabifire?060320 To make it easier for new users to understand the firewall building script I have added two new options to print 'iptables' commands before they are executed and to not execute them. Linux networking Netfilter iptables shell firewall IP IPv6 configuration Mon, 20 Mar 2006 16:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060319c After adding a shell script for firewall configuration, reflections on how subtle and complex it is, and the firewall configuration it generates too, and how users mistakes physical accessibility of the sources and distributions of free software with their accessibility in a skills sense. Linux networking Netfilter iptables shell firewall IP IPv6 configuration http://www.sabi.co.uk/Notes/anno06-1st.html#060319c Sun, 19 Mar 2006 23:50:00 +0000 http://WWW.sabi.co.UK/#sourcesSabifire Just added a shell script to set up a leaf node firewall configuration for Linux using Netfilter. Linux networking Netfilter iptables shell firewall IP IPv6 configuration Sun, 19 Mar 2006 23:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060319b AMD may be interested in using a ClearSpeed coprocessor to enhance the floating point performance of its CPUs. The ClearSpeed architecture presents some challenges. CPU parallelism AMD http://www.sabi.co.uk/Notes/anno06-1st.html#060319b Sun, 19 Mar 2006 22:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060319 After cleaning the lower front filter for the air intake of my PC case temperatures of the hard disks and the CPU and chipset dropped significantly. hardware cooling case http://www.sabi.co.uk/Notes/anno06-1st.html#060319 Sun, 19 Mar 2006 22:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060315b The syntax for defining and making use of ALSA parametric devices seems obscure, but I have eventually managed to figure it out, at least in part. Linux sound ALSA asound.conf http://www.sabi.co.uk/Notes/anno06-1st.html#060315b Wed, 15 Mar 2006 23:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060315 Classic example of not very useful messages because of their incompleteness. Linux sound ALSA http://www.sabi.co.uk/Notes/anno06-1st.html#060315 Wed, 15 Mar 2006 19:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060314c A 19" inch widescreen monitor has less pixels than a 17" one. Quoting monitor diagonals only makes much sense if the aspect ratio is not much more oblong than the classic 4x3 one. hardware LCD monitor http://www.sabi.co.uk/Notes/anno06-1st.html#060314c Tue, 14 Mar 2006 18:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060314b An important property in UNIX like systems is that data be easily sortable. It is very annoying that internet domain names and IP addresses in dotted quad notation don't sort naturally. UNIX pragmatics programming http://www.sabi.co.uk/Notes/anno06-1st.html#060314b Tue, 14 Mar 2006 17:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060314 Nice test of two otherwise very similar top end videocards, with 256MiB and 512MiB. At top quality several modern games use way more than 256MiB of texture memory. Indeed at lower resolutions and memory they use more than 128MiB... videocards videogames NVIDIA http://www.sabi.co.uk/Notes/anno06-1st.html#060314 Tue, 14 Mar 2006 17:35:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060313 Someone has checked how much shared libraries cost in CPU time. Not a lot in itself, but it adds up to a significant overhead. Linux shared libraries ELF http://www.sabi.co.uk/Notes/anno06-1st.html#060313 Mon, 13 Mar 2006 20:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060312d Mark Shuttleworth proposes a delay in the next Ubuntu release, and his reasons have to do with polishing it into an enterprise level distribution Linux Debian Ubuntu http://www.sabi.co.uk/Notes/anno06-1st.html#060312d Sun, 12 Mar 2006 15:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060312c Using the Cell processor in IBM blade server, some not so fresh news. Cell PS/3 IBM Sony http://www.sabi.co.uk/Notes/anno06-1st.html#060312c Sun, 12 Mar 2006 15:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060312b Microsoft and UofM have crated some virtual machine based rootkits as a proof of concept. Isn't DRM based on VM technology similar? Microsoft security virtual machine DRM http://www.sabi.co.uk/Notes/anno06-1st.html#060312b Sun, 12 Mar 2006 15:35:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060312 Comments on Sony's plans to deliver PS/3 before the end of the year, on the meaning of 'spring' as a delivery date, and Sony's hopes that in Europe those that purchase Xbox 360 will also buy a PS/3, despite the high prices of both. Xbox 360 PS/3 Dell Sony Nintendo Microsoft videogames http://www.sabi.co.uk/Notes/anno06-1st.html#060312 Sun, 12 Mar 2006 14:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060309b Sony is sticking to its promise of a spring 2006 launch for PS/3, and there is speculation on the launch price. Probably PS/3 will be launched at the end of June 2006, in very limited quantities, just the like Xbox 360, and at a price, like the Xbox 360, which overlaps with the price range of low end PCs. Xbox 360 PS/3 Dell Sony Nintendo Microsoft videogames http://www.sabi.co.uk/Notes/anno06-1st.html#060309b Thu, 09 Mar 2006 18:55:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060309 The specification for the Nintendo Revolution are not yet public, but it seems like that it will have fewer processors and much more cache than PS/3 or Xbox 360, and this will make it rather competitive. Revolution PS/3 Xbox 360 Sony Nintendo Microsoft videogames http://www.sabi.co.uk/Notes/anno06-1st.html#060309 Thu, 09 Mar 2006 17:35:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060306b After two months of using my new fast 250GB discs I am retesting how much performance in my root partition has degraded. About twice, which is not too bad. JFS file system Linux performance fragmentation http://www.sabi.co.uk/Notes/anno06-1st.html#060306b Mon, 06 Mar 2006 20:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060306 Intel will stop doing hyperthreaded CPUs, as it is switching to multiple cores. But recent game consoles are still in effect HyperThreaded. Hard to exploit. Intel HyperThreading dual core games PS/3 Xbox/360 http://www.sabi.co.uk/Notes/anno06-1st.html#060306 Mon, 06 Mar 2006 19:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060305 Lionhead are downsizing, and give numbers on how many developers they retain for how many projects, giving a rough indication of next gen team size. videogames PS/3 Xbox/360 http://www.sabi.co.uk/Notes/anno06-1st.html#060305 Sun, 05 Mar 2006 14:15:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060226c Source has been released a while ago for the splendid EECH games (Comanche Hokum and Apache Havoc), and a still active community produces extension and mods. videogames simulation http://www.sabi.co.uk/Notes/anno06-1st.html#060226c Sun, 26 Feb 2006 23:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060226b There are really few online player for some popular games. I guess that they are all playing WoW. videogames online MMORPG http://www.sabi.co.uk/Notes/anno06-1st.html#060226b Sun, 26 Feb 2006 23:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060226 KIAX version 0.8.5 is more polished and useful. Too bad ALSA support is still missing. VoIP IAX2 KIAX http://www.sabi.co.uk/Notes/anno06-1st.html#060226 Sun, 26 Feb 2006 23:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060219b Firefox gets mocked a bit for memory leaking, in particular an intentional one, which however is misguided... web browser Mozilla Firefox Konqueror http://www.sabi.co.uk/Notes/anno06-1st.html#060219b Sun, 19 Feb 2006 21:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060219 Found an interesting video of a seminar about the design the the Reiser4 file system, and the aim to escape purely hierarchical or tabular arrangements. file system naming Linux http://www.sabi.co.uk/Notes/anno06-1st.html#060219 Sun, 19 Feb 2006 17:10:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060212 An informal interview with a PS/3 developer reveals that many PS/3 will not manage 1080p except via upscaling, and that some people have been doing software anti-aliasing on it, presumably using one or more SPEs. PS/3 videogames parallelism CPU GPU graphics http://www.sabi.co.uk/Notes/anno06-1st.html#060212 Sun, 12 Feb 2006 22:30:00 +0000 http://WWW.sabi.co.UK/#sourcesDokde Updates and fixes to my version of the KDE startup script. Linux X11 KDE configuration Sun, 12 Feb 2006 21:55:00 +0100 http://WWW.sabi.co.UK/blog/anno06-1st.html#060204b An Intel paper discusses ELF performance improvements, and in particular the ''visibility'' issues, with some details. ELF Linux Intel http://www.sabi.co.uk/Notes/anno06-1st.html#060204b Sat, 04 Feb 2006 15:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060204 Which motherboards do ECC given ECC RAM? Not many, and here are some pointers by chipset and by model. hardware RAM memory ECC motherboard http://www.sabi.co.uk/Notes/anno06-1st.html#060204 Sat, 04 Feb 2006 15:25:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060203 it is not clear why Apple switched to Intel, as the Core Duo is a pretty good chip for laptops. It is also interesting that Intel is playing low price alternative to AMD's leading dual core chips. hardware Apple Intel dual core CPU http://www.sabi.co.uk/Notes/anno06-1st.html#060203 Fri, 03 Feb 2006 22:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060201 Ray tracing is another possible use of those 7 SPEs in a PS/3. Remembering the Transputer. And what about in-game movies? PS/3 simulation videogames parallelism CPU GPU graphics ray tracing http://www.sabi.co.uk/Notes/anno06-1st.html#060201 Wed, 01 Feb 2006 22:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060130 Just discovered that a manufacturer offers a reduced spin-up current option for 2.5" drives meant to be used in external USB/FW2 boxes. hard disc PSU http://www.sabi.co.uk/Notes/anno06-1st.html#060130 Mon, 30 Jan 2006 22:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060129c As a smart friend points out, lack of security measures gives the same false sense of security as lack of ECC for RAM. security auditing memory RAM ECC http://www.sabi.co.uk/Notes/anno06-1st.html#060129c Sun, 29 Jan 2006 17:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060129b As a smart friend points out, RAID5 also implies a lot more disk operations for the same amount of data, which can mean a lot more wear and tear of the hard discs. storage system administration http://www.sabi.co.uk/Notes/anno06-1st.html#060129b Sun, 29 Jan 2006 17:25:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060129 Some benchmarks shows that WINE under GNU/Linux is often as good or better than MS Windows at running WIN32 programs. Linux GNU WIN32 WINE WINE OpenGL benchmark http://www.sabi.co.uk/Notes/anno06-1st.html#060129 Sun, 29 Jan 2006 17:15:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060128c Looking at an impressive chart of the number of MMORPG players over time suggests that the MMORPG industry is taking a lot of customers and revenue from the PC game industry. games MMORPG PC sales http://www.sabi.co.uk/Notes/anno06-1st.html#060128c Sat, 28 Jan 2006 18:35:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060128b Sony game consoles are probably designed for the benefit of their signature games, primarily Grant Turismo, and this may mean that the PS/3 is designed for partitioning load by actor, not by global effect or game pipeline step. games PS/3 parallelism SMP http://www.sabi.co.uk/Notes/anno06-1st.html#060128b Sat, 28 Jan 2006 17:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060128 The driver of most upgrades to my PC has been increased game requirements. games GPU SMP technology http://www.sabi.co.uk/Notes/anno06-1st.html#060128 Sat, 28 Jan 2006 17:20:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060127b RAID10 is over 10 times faster than RAID5 for backups, an even more dramatic difference than expected. RAID5 RAID10 disk backup http://www.sabi.co.uk/Notes/anno06-1st.html#060127b Fri, 27 Jan 2006 21:30:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060127 I have sold out, or rather bought in 1GiB RAM, and things are so much better than with 512MiB that it is likely most kernel/KDE/GNOME developers have at least 1GiB themselves. Linux RAM ECC 1GiB swapping virtual memory KDE http://www.sabi.co.uk/Notes/anno06-1st.html#060127 Fri, 27 Jan 2006 21:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060113 Found a nice photo of a high speed 3.5" disc drive which shows it actually has 2.5" platters. hard disk hard drive performance ATA http://www.sabi.co.uk/Notes/anno06-1st.html#060113 Sat, 13 Jan 2006 12:15:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060111 A friend has sent me a link to an extensive test of compression programs, which includes decompression speed. Linux GNU compression decompression http://www.sabi.co.uk/Notes/anno06-1st.html#060111 Wed, 11 Jan 2006 22:10:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060105c All games are becoming mods, and some games are developed almost only to showcase a game engine which is the real source of profits for the game studio developing both game and engine. games marketing game engine http://www.sabi.co.uk/Notes/anno06-1st.html#060105c Fri, 05 Jan 2006 21:45:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060105b This interview is rather expansive and contains a discussion of PC game piracy (with some dodgy arguments) and on console development: if it looks like a PC it is good. games mobile phones Xbox 360 PS/3 http://www.sabi.co.uk/Notes/anno06-1st.html#060105b Fri, 05 Jan 2006 20:40:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060105 John Carmack comments on mobile phone games and toolkits for them. games mobile phones Doom BREW J2ME Java http://www.sabi.co.uk/Notes/anno06-1st.html#060105 Fri, 05 Jan 2006 20:15:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060102 Found a page with a list of preferred command line programs, so some comments and additions. curses web shell command line http://www.sabi.co.uk/Notes/anno06-1st.html#060102a Mon, 02 Jan 2006 16:05:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060101 When buyer fail to appreciate the importance of a feature of a product, like maximum spin up current or longest seek time, the feature stops being mentioned in the specifications and then itself becomes worse. For example this has happened to ECC support in motherboard chipsets, which is a very important and nearly free feature. hard drive performance ECC RAM http://www.sabi.co.uk/Notes/anno06-1st.html#060101 Sun, 01 Jan 2006 16:50:00 +0000 http://WWW.sabi.co.UK/blog/anno06-1st.html#060101 When buyer fail to appreciate the importance of a feature of a product, like maximum spin up current or longest seek time, the feature stops being mentioned in the specifications and then itself becomes worse. For example this has happened to ECC support in motherboard chipsets, which is a very important and nearly free feature. hard drive performance ECC RAM http://www.sabi.co.uk/Notes/anno06-1st.html#060101a Sun, 01 Jan 2006 15:15:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051227b More thinking on the various conflicting requirements for my upgrade main drive and its 3 backup drives. The GHST and Maxtor drives match my requirements for both internal and external drives, but I also want diversification of manufacturer. hard drive performance storage backup http://www.sabi.co.uk/Notes/anno05-4th.html#051227b Tue, 27 Dec 2005 18:20:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051227 It happens fairly often that my Linux desktop has to swap in processes paged out because of memory pressure, and this happens at 1MiB/s on a disc capable of 40MiB/s, because of lots of arm movement. No relief in sight. Linux performance virtual memory swapping http://www.sabi.co.uk/Notes/anno05-4th.html#051227 Tue, 27 Dec 2005 18:00:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226e To enjoy fast disc performance one can buy a large desktop disc and then use only its outer cylinders. hard drive performance server DBMS http://www.sabi.co.uk/Notes/anno05-4th.html#051226e Mon, 26 Dec 2005 23:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226d Having played some not so recently released FPS games on my average PC they end up with low frame rates. graphics GPU game FPS http://www.sabi.co.uk/Notes/anno05-4th.html#051226d Mon, 26 Dec 2005 23:25:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226c Hoping to upgrade my desktop PC to some larger discs, I consider also spin-up power draw as some of those discs will end up as backup discs in an external USB case. Only a few models can do. hard drive USB2 Firewire PSU http://www.sabi.co.uk/Notes/anno05-4th.html#051226c Mon, 26 Dec 2005 22:50:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226b Four weeks ago I reinstalled from scratch my Linux root partition, and I have been regularly upgrading it. How much slower overall has it become? Only 1.8 times slower with JFS. filesystem Fedora speed JFS http://www.sabi.co.uk/Notes/anno05-4th.html#051226b Mon, 26 Dec 2005 22:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051226 Some comments on an interesting article as to performance of a Quake 4 update that is multithreaded to take advantage of hyperthreading or multiple CPUs, and some comments on general strategies to achieve good speedups. game Quake 4 hyperthreading SMP Intel AMD http://www.sabi.co.uk/Notes/anno05-4th.html#051226 Mon, 26 Dec 2005 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051219 Having switched from FAT32 to 'ext2' the filesystems I share between MS Windows and GNU Linux on my home PC a few weeks ago, so far I am quite happy with it. Linux MS Windows FAT32 ext2 http://www.sabi.co.uk/Notes/anno05-4th.html#051219 Mon, 19 Dec 2005 22:05:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051217 When optimizing vector codes especially on CPUs with SIMD oriented operations it is quite useful to avoid expression oriented constructs like 'x = y + z', and just use ''and becomes'' oriented APIs, like 'x = y; x += z'. vector architecture optimization http://www.sabi.co.uk/Notes/anno05-4th.html#051217 Sat, 17 Dec 2005 17:15:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051216 I have found a book that contains a number of mostly well written essays on improving memory reference locality. It is amazing that however little this is practiced it is not yet a totally forgotten area. optimization architecture locality memory cache http://www.sabi.co.uk/Notes/anno05-4th.html#051216 Fri, 16 Dec 2005 22:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051204 Very interesting and unexpected performance issues with filesystems, in particular 'ext3' with the 'dir_index' option. UNIX Linux Fedora filesystem ext3 JFS http://www.sabi.co.uk/Notes/anno05-4th.html#051204 Sun, 04 Dec 2005 21:45:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051203 Comparison of 'bunzip2', 'gunzip' and 'lzop -d' as to decompressing archives containing the same data. UNIX Linux lzop bunzip2 gunzip compression decompression http://www.sabi.co.uk/Notes/anno05-4th.html#051203 Sat, 03 Dec 2005 20:10:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051202b After the release of KDE 3.5, some Fedora 4 RPMs are now available. Linux RedHat Fedora RPM KDE http://www.sabi.co.uk/Notes/anno05-4th.html#051202b Fri, 02 Dec 2005 18:55:00 +0000 http://WWW.sabi.co.UK/blog/anno05-4th.html#051202 Some people have run Doom III on a Voodoo 2 SLI graphics card, which does not have bump mapping. This makes clear just how simple is the geometry in Doom III and how effective bimp mapping at adding detail. games Doom III graphics OpenGL http://www.sabi.co.uk/Notes/anno05-4th.html#051202 Fri, 02 Dec 2005 17:50:00 +0000