Author: Vincent Diepeveen
Date: 07:13:50 07/03/05
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On July 03, 2005 at 08:02:49, Amir wrote: >On July 03, 2005 at 07:21:55, Vincent Diepeveen wrote: > >>On July 03, 2005 at 06:57:42, Amir wrote: >> >>>On July 03, 2005 at 06:50:23, Vincent Diepeveen wrote: >>> >>>>On July 03, 2005 at 06:10:37, Amir wrote: >>>> >>>>>I have noticed that playchess.com software tells you the opponents KN/s after >>>>>each game. Can anyone who has played Hydra (the new version -- Ares01) posts >>>>>it's KN/s? >>>> >>>>It had about 220 million nps against us. >>>> >>>>Note that hardware nodes are not like software nodes. >>> >>>so 220 million nps is average for Hydra? >> >>it is hardware, so it gets in endgame not more nodes than it gets in opening. >>arguably in endgame it gets less nps than opening because the treesize of 1 >>search of 2 to 3 ply is smaller. >> >>so yes 220 mln is average for 32 processors. please note i calculated theoretic >>peek of it at 320 mln nps for 32 fpga chessprocessors. the machine has room for >>64 fpga processors in total. >> >>1 fpga chessprocessor can get clocked at like 60-66Mhz easily. >> >>So I calculated peek at theoretic 60Mhz, that's very pessimistic taken. >>Important runs they will clock it a tad higher to 66Mhz or so. >> >>So on paper the real theoretic peek is even higher in reality. More like 400 mln >>nps, but you never get your peek in hardware of course. >> >>There is latency of pci bus, there is time needed to put all cpu's to work and >>so on. >> >>By the way, my own experiments at supercomputers indicated that 16 cpu's is most >>easy to get a good speedup from, relative seen. 32 cpu's it is a lot hardware, >>but putting 32 cpu's to work is real easy. Yet the extra speedup you get from >>moving from 16 to 32 cpu's is not so big. Not only speedup gets bigger, also the >>worst case speedup still is utmost tiny. >> >>But the nodes per second out of 32 fpga processors being 220 million is very >>constant. It hardly fluctuates. It's not that 1 run it's 50 million and the next >>one 500 million. It's simply always around that 220 million. > >Since the cluster is 64 CPUs, what would be the nps when they get 32 more FPGA >cards? the nodes per second is not so important. the speedup is. i expect not much better speedup. but of course it will scale well when putting the hashtable depth probe higher. so the nps will nearly increase lineairly.
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