Author: Robert Hyatt
Date: 11:29:05 09/04/02
Go up one level in this thread
On September 04, 2002 at 14:02:54, Vincent Diepeveen wrote:
>On September 04, 2002 at 12:43:37, Robert Hyatt wrote:
>
>Please run crafty at 16 processors. Fine with me.
>Even though it's a different program. I have no problems
>with it.
And what would be the point? I might give you some 16 processor
numbers on a NUMA machine before long. I _might_.
>
>But rewrite also the article then that it's not a DTS thing,
>but a smp_lock thing that doesn't scale above 8 cpu's.
Vincent, the smp_lock thing doesn't hurt me thru 16 cpus as I already
know. I don't understand why you don't follow this, but in a typical
3 minute search, I see numbers like this:
time=3:29 cpu=399% mat=0 n=303284136 fh=89% nps=1450k
ext-> chk=4663926 cap=1175890 pp=230533 1rep=74539 mate=3299
predicted=2 nodes=303284136 evals=99342268
endgame tablebase-> probes done=0 successful=0
SMP-> split=774 stop=133 data=14/64 cpu=13:55 elap=3:29
That is from a real game played on ICC.
Note it only did 774 splits. that is 774 smp_locks. Do you _really_ think
that hurts performance? _really_?
If so, I have this bridge I need to get rid of...
You can say smp_lock is a problem all you want. You can say that it killed
you on a NUMA machine all you want. But that doesn't mean it kills _me_
on 8 or 16 processors...
BTW I would hate to publish 16 cpu crafty numbers, because that would probably
give you _another_ problem to overcome with your "sponsors". :)
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