Linux SMP Round-Up
Dual Minds writes "LinuxHardware.org is at it again and this time they cover three of the finest boards on the market. This review covers three dual processor Xeon boards and they are the only site that ever does Linux reviews (at least on a regular basis). Here's a peak: "First thing is that all E7505-based boards are basically the same on the surface due to the basic features of the chipset. They all have dual processor support, support for dual channel DDR, and support for PCI-X up to 133MHz (to name a few). Once a manufacturer gets their hands on the board though, features can be added or it can simply be left as is." Very in depth and some sweet hardware."
yes, linux 'supports' hyperthreading - that took no changes at all, since they just show who up as more CPU targets. 2.5 kernels, and (I think) some of the 2.4 scheduler patchsets, also have some special tuning to avoid some of the worse behaviors hyperthreading can cause (when processes hop back and forth between physical images cores, or end up overcrowded on one virtual image).
:-)
So linux support for HT is pretty good
The Matrix is going down for reboot now! Stopping reality: OK. The system is halted.
Quake3's smp only works with Nvidia TNT2 cards under NT4.
This is just not true. Quake 3 smp also works under Mac OS X and it does has a large impact on FPS.
Linux does support hyperthreading. 2.4.20 recognizes four processors on my dual Xeon servers, without any tweaks. I think it's pretty nice -- I'd say there's between a 5% and 25% pickup in performance, depending on what you're using it for (generic vs. optimized integer code).
According to a geek.com article, Linux was actually the first operating system to officially support hyperthreading, and that was in late 2001.
The PCI-X controller used in almost all of the E750x workstation/server boards is really expensive and adds to the complexity of the board layout and design. It seems that Tyan decided to forgo that chip in order to keep the cost of the board down while making up for it by adding Serial ATA (but no FireWire like it's larger Thunder i7505 brother).
One board that I would like to have seen reviewed is the Supermicro X5DAL (with or without Serial ATA RAID) as it does include PCI-X slots, but it is also a standard ATX-sized motherboard. It only has four memory slots, so that may have changed some of the memory timings and possibly have improved some of the scores by a small amount.
One a side note, FreeBSD 4.8-RELEASE users will also benefit from the newly added support for HyperThreading found in all P4-based Xeons and the 3.06GHz P4. More info can be had here. I'm not sure if that feature is also available in 5.0-CURRENT (I would think it would be MFC).