Author: Robert Hyatt
Date: 21:34:05 04/25/01
Go up one level in this thread
On April 26, 2001 at 00:01:15, Chessfun wrote: >On April 25, 2001 at 23:32:01, Robert Hyatt wrote: > >>On April 25, 2001 at 15:49:58, Frank Quisinsky wrote: >> >>>Hi there, >>> >>>I gave Crafty 2 CPUs, see the np/s from Chess Tiger. >>>The games will be replayed. >>> >>>:-(( >>>Frank live ... >>>I forgot to adjust "Thread = 1" in the options from Crafty :-( >>> >>>Best >>>Frank >> >> >>Ugh.. if that is on a dual, it will kill my program. I get two threads >>going, tiger has a third, and that is bad. It is quite possible that I >>was searching nothing much at all in some cases. >> >>The problem is that one thread might be sitting on a spinlock and running >>while the other thread is not executing due to Tiger. That is just wasting >>the second cpu. Crafty's parallel search _absolutely_ must have 100% of all >>the processors you use it on... or it will die horribly. >> >>It doesn't like 'shared machines' for the parallel search. _ever_. It isn't >>harmful for the serial search of course. But for the parallel search, it is >>awful. > >Frank has been running this CCE tourney for months. >He is running it on a dual computer. > >This is not a SMP crafty as far as I know nor is it meant to be. >All programs have identical hardware a single cpu. > >Sarah. His previous post implied crafty was "trying" to use two threads. If it was, the result is bad for several reasons. Tiger would get 1/2 of one CPU. But then Crafty's SMP search would perform poorly. Random results for sure which should be avoided...
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