Author: Robert Hyatt
Date: 11:23:51 04/10/03
Go up one level in this thread
On April 10, 2003 at 11:18:43, Charles Worthington wrote: >To me, at this point, the jury is still out on 4 threads vs. two. I could run >the machine on 2 threads on the server and see what results I get but those >results would be meaningless because I have no way of knowing if the machine >would have played any better or worse using all 4 threads in identical positions >against identical opponents. The deepfritzmark test clearly shows an increase in >the performance of Deep Fritz 7 on dual threads vs four_but_ a significant >slowdown in nodes per second. This seems contradictory and had I gotten the same >result from Shredder I would have been suspicious as to the accuracy of that >particular benchmark test....but I didn't. Shredder showed a significant benefit >in both nps and time-to-solution with hyperthreading enabled. But the fritz >result is baffling: On the surface a 10% speedup in nodes per second should >result in a 10% increase in the number of positions reviewed by the program. It >should also result in greater ply depth. The faster the machine searches, the >faster it should be able to solve the fritzmark position. This seems like common >sense to me. So, my question is this: Is the fritz benchmark somehow more >innacurate than shredder's or is the reasoning I am using here somehow flawed? > >Charles Look at the data I posted. The jury is back in and the verdict is "it works". Be sure than when you test a multi-threaded program, you run several positions and you run each position multiple times to be sure you are not looking at a single anomaly vs actual expected results... That's why I ran four positions that Vincent seems to like, three times each (and no I didn't re-run with a filled hash table the second and third time, Vincent...) That lets me see how consistent the results are and if there are any problematic positions that need to be run even more times to reach some sort of stability in the speedup number...
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