Author: Anthony Cozzie
Date: 09:16:35 01/02/04
Go up one level in this thread
On January 02, 2004 at 11:24:19, Steven J. Brann wrote: >On January 02, 2004 at 11:05:41, Anthony Cozzie wrote: > >>On January 02, 2004 at 09:57:38, Jasmine Baer wrote: >> >>>I've seen it written that under the following conditions: >>> >>>1. Engine vs. Engine match or tournament >>>2. Held on a single computer with a single processor >>> >>>having ponder=ON(or Permanent Brain in the Fritz GUI) will impact the play of >>>the engines since the each individual engine would not have full access to the >>>processor during its own turn. >>> >>>First, is this true? >>> >>>Second, is this issue, if it actually is an issue, something that is eliminated >>>by running a two-processor system? >>> >>>And, finally, does anyone have any solid insight on how ponder=off/on or >>>Permanent Brain works on a Pentium 4 with Hyperthreading? >>> >>>Thanks. >> >>Ponder means that the engine thinks while its opponent moves. Since there is >>only 1 cpu, and both engines are thinking, they get half the cpu. >> >>HT is garbage for computer chess. A pentium 4 is ONE core. HT is designed for >>applications that spend most of their time in the memory system. >> >>anthony > >To me, my 3.0G HT machine is NOT garbage for computer chess. When it is >thinking about a position it takes up 50% of the CPU and is still much much >faster than my 1.9G P4 machine. When analyzing a position with my 1.9G P4, the >machine would be rendered useless for using any other application while it was >thinking about a position. > >So, HT enables me to accomplish other things on the machine at the same time ... >email, reviewing this site, chat with video, Word, Excel ... and >performance-wise its as if the chess program isn't running at all. I'm >analyzing a position as I write this. > >That means a lot to ME. Certainly not garbage in my opinion. > >Steve I'm only going to say this once, so pay attention. A P4 with hyperthreading is _A SINGLE CPU_ that _TRICKS_ windows into thinking it is two. If you still think you have two CPUs, try running two chess engines at once. I did not say "P4 is worthless for computer chess" (although I prefer my dual opteron :). My point is just that if Intel removed HT from the chip you would not know the difference. Everywhere I go I run into people that think its two CPUs. Its unbelievably annoying. The reason Intel put hyperthreading in the P4 is to help it with databases. When a running a database, the processor spends a lot of time waiting for memory. With HT, it can get useful work to do from the other thread while one blocks on the memory system. anthony
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