Author: Tom Kerrigan
Date: 14:13:53 03/24/02
Go up one level in this thread
On March 24, 2002 at 00:02:50, Robert Hyatt wrote: >On March 23, 2002 at 16:09:55, Tom Kerrigan wrote: > >>On March 23, 2002 at 13:38:45, Dan Andersson wrote: >> >>>SMT is of little or no consequence to chess programs. It might even slow it >>>down. You don't think it automatically doubles the amount of functional units on >>>a given CPU, do you? >> >>You're completely missing the point. SMT was invented and implemented because >>most of a chip's functional units are idle at any given point in time--using >>them for another thread gives you free performance. >> >>I haven't seen any benchmarks yet, but a quad P4 Xeon will appear to software as >>an 8-way system and while it will probably not be as fast as a full-on 8-way >>system, it will be much faster than a 4-thread system. >> >>-Tom > >This is only true of _one_ of the two threads can run mainly out of cache. >The processor will have the other thread stalled waiting on memory reads or >writes. If the second thread needs memory, it is over... But if it can run >out of cache, it can fill in the gaps nicely... Do you have a reference for the P4 only switching threads on main memory accesses? -Tom
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.