Author: Martin Baumung
Date: 03:24:12 11/01/05
Go up one level in this thread
On November 01, 2005 at 06:17:59, Gabor Szots wrote: >On November 01, 2005 at 05:58:14, Gian-Carlo Pascutto wrote: > >>On November 01, 2005 at 05:44:34, Gabor Szots wrote: >> >>>I just got a new machine with P4 3GHz CPU. Analyzing positons with chess >>>programs I looked at task manager and was surprised by seeing that only 50% CPU >>>was assigned to the chess program thread while the other 50% was idle. >>>I tried the same with Deep Sjeng with 2 processor setting and I saw 2 50% CPU >>>threads while the system was idle 0%. Ok, however the Nps was the same as with >>>only 1 processor, and test solution times were also the same. >>>This all was under WinXP SP2. >>> >>>How can I exploit full CPU power? Any explanation would be welcome. >> >>A system with hyperthreading really only has a single processor, it just >>pretends there are two. At best you will get a few percent speedup. >> >>A real dual core processor will give >70-80% speedup. >> >>-- >>GCP > >The problem is that the system behaves as though the CPU ran at only 1.5 Ghz >instead of 3. If there is only 1 thread, why do the chess programs not use >'both' CPU's? I think both halves of the CPU should process that single thread >simultaneously, thereby adding their 1.5 Ghz speeds together. >I have a feeling that I don't understand this at all. I don't want a speedup, I >would like to avoid a slowdown. You have no slowdown Gabor. As you wrote above Deep Sjeng's NPS value is the same regardless of how many threads it uses. And that '50% problem' only is a cosmetic one... Martin
This page took 0 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.