Author: Vincent Diepeveen
Date: 19:30:47 09/16/03
Go up one level in this thread
On September 15, 2003 at 14:16:38, Robert Hyatt wrote: >On September 15, 2003 at 13:18:28, Gian-Carlo Pascutto wrote: > >>On September 14, 2003 at 12:52:54, Sietel Monic wrote: >> >>>My friend runs dual proccessors using hyperthreading so gets 4 threads, I know >>>this is bad for chess. Just dont know why >> >>This is ok. Running with 2 threads on a dual processor with hyperthreading >>enabled is _not_, unless you're running Linux 2.4.x or Windows Server 2003. You sure of this bob? QUADopteron:/diep/latency # uname -a Linux QUADopteron 2.4.19-NUMA #3 SMP Wed Jul 2 18:34:37 CDT 2003 x86_64 unknown Perhaps all you need is a special extension to the kernel. >Linux 2.4.x won't cut it either. I use 2.4.21 and it is _not_ SMT-aware. IE >it will certainly recognize 4 processors, but it doesn't realize that if there >are just two computational tasks to run, they should be run on two physical >processors. 2.4 just runs them on any two logical processors. When the two >logical processors are on one physical processor, this performs poorly. Ingo >Molnar did a scheduler that addresses this (or maybe Rick did it). And it works >well (it has two run queues, one for each physical procesor, rather than four, >one for each logical processor.) But that isn't in mainstream 2.4 yet (I have >not looked at 2.4.22 closely so it _could_ be there). > >> >>-- >>GCP
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.