Author: Robert Hyatt
Date: 06:44:34 11/01/05
Go up one level in this thread
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. > >Gábor that is simply misleading info from task manager. HyperThreading shares internal CPU pipelines. I can guarantee you that Crafty is using 100% of the processor, or nearly so. Turning SMT on will actually hurt performance for Crafty, as it will increase the raw NPS by 10%, but the parallel search overhead will eat up 15% of the total NPS which means this is a net performance loss. Don't turn SMT on for Crafty... And ignore task manager here, it doesn't know what it is reporting...
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.