Author: Peter Berger
Date: 08:20:42 07/15/04
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On July 15, 2004 at 11:11:40, Robert Hyatt wrote: >On July 15, 2004 at 03:45:46, Peter Berger wrote: > >>On July 14, 2004 at 22:19:12, Robert Hyatt wrote: >> >>>>I say "at least 4x", because each of those Opteron processors was faster than my >>>>2.0GHz AMD 64. In fact I think it was quite more than 4x... >>> >>>Bad math. Here is the correct math. >>> >>>I had 4 X 2.4ghz. You had 1 X 2.0ghz. >>> >>>My SMP speedup is about 3.1X. that gives me 3.1 * 2.4ghz effective speed. IE >>>7.44ghz. I also lose another 10% overall as that machine did not have all the >>>working NUMA kernel stuff, so that drops to about 6.7ghz effective speed. >>> >>>The difference was really about 3.3x at best... >>> >>>Those with numbers that anyone can verify. >> >>There is some additional speedup (at least for Crafty, for Falcon I have no >>idea) from running in 64bit mode. Falcon's computer was running Windows XP. >> >>For Crafty the speedup would have indeed been about 4 . > >I don't understand. The SMP search definitely is about 3.1x faster. I've >posted the data to show this and its on my ftp box already. The raw NPS was off >about 10%, which is the gain possible with the libNUMA things that I could not >get working on such short notice. IE on a quad 2.4 I should get close to 4x the >raw NPS. I did not. Each CPU ran about 10% slower on average than a single CPU >2.4 would run, because of this. > >It doesn't really matter how it compares to another program. I actually have >some logs from some 2.0ghz runs prior to the last CCT, where I ended up on a >2.2ghz box. That was what I used to do the above computations... I assume you used Linux in 64 bit mode on the single-CPU-Opteron too, so you measured only the real speedup from the additional processors. If Crafty had used Windows XP on the single Opteron it would have been slower. Actually we have no disagreement here - I simply compaired Omid's system as was with ours and concluded a plausible speedup number for Crafty, as I can't do it for Falcon for obvious reasons. Peter
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