Author: Slater Wold
Date: 18:18:42 09/05/02
There has been a fairly large debate lately over 'speedup'. The problem: 1 CPU: 800k NPS & 60 seconds to solve position 2 CPUs: 1600k NPS & 45 seconds to solve position What's the "speedup"? As far as I can tell, most super-computer manufacturers and parallel design "specialists" define speedup as "the ratio of the serial run time of a parallel application for solving a problem on a single processor, to the time taken by the same parallel application to solve the same problem on n processors". RSn = T1/Tn Today I ran the WAC suite using Crafty 18.15 (SMP) from Hyatt's FTP site. One using just 1 CPU, and the other using both. Using these 300 positions, I plan to determine if their is any link between an increase in NPS and an increase in solve time. I will try a few different compiles of Crafty. The first one yielded a *horrible* NPS speedup in the first 100 positions (1.23). [D]1k6/5RP1/1P6/1K6/6r1/8/8/8 w - - (WAC 41) Average NPS using 1 CPU: 1503k NPS Average NPS using 2 CPUs: 1786k NPS Time to 11th ply using 1 CPU: 48.36 seconds Time to 11th ply using 2 CPUs: 2.99 seconds [D]r1b1qrk1/2p2ppp/pb1pnn2/1p2pNB1/3PP3/1BP5/PP2QPPP/RN1R2K1 w - - (WAC 76) Average NPS using 1 CPU: 804k NPS Average NPS using 2 CPUs: 1306k NPS Time to 11th ply using 1 CPU: 19.39 seconds Time to 11th ply using 2 CPUs: 13.42 seconds These 2 logs are *full* of these kinds of things. Any comments/thoughts/ideas/suggestions welcome.
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