Author: Uri Blass
Date: 10:50:53 05/27/05
Go up one level in this thread
On May 27, 2005 at 11:54:03, Torstein Hall wrote: >On May 27, 2005 at 08:45:58, Vincent Diepeveen wrote: > >>On May 26, 2005 at 16:29:46, Joshua Shriver wrote: >> >>>Interesting... so how many of the 32 cpu's are CPU vs FPGA custom chips? >> >>It has 32 custom FPGA cards. >> >>>Have there been any stats as to nps on each fpga, and what kind of bus does it >> >>You are interested in objectivity, the hydra team is a very bad person to ask in >>that case. They are interested in blowing it up to unheard dimensions. >> >>>rest on? I thought the FPGA's where attached on a PCI backplane, and if they're >>>working with that many, have they come across any latency problems over the PCI >>>bus. >> >>That's why they do not have hashtables inside the fpga cards. >> >>>Hydra intrigues me, since parallel programming is what inspired me to want to do >>>an engine. (Besides also loving the game) >> >>Their parallel algorithm isn't worth much in the real world i guess. I don't >>give a penny for their parallel efforts. If they would have a good parallel >>algorithm, hydra would already run at 1024 cpu's by now for sure. >> >>Also the way it gets shown to the world is kind of the usual way. >> >>First dumb down 1 cpu a lot by not using hashtable last 6 ply, then show a good >>speedup of a lobotomized 1 cpu versus 32. >> >>We know that drill from the past already. >> >>Like cilkchess (MiT), a fast bitboard engine, getting just like 2500-5000 nodes >>a second at a single cpu at 512 cpu's 500Mhz, and diep a program 20 times >>faster, gets at the same hardware at 512 cpu's 10000-20000 nodes a second a cpu. >> >>I mean, cilkchess team can claim whatever speedup they have, but without cilk >>their program at 1 such cpu gets 200000 nodes a second, as it's a simplistic >>bitboards engine with near to no eval (crafty has 4 times more knowledge in eval >>than cilkchess in fact). So from my viewpoint they are missing a factor 40+ >>somewhere in the compare to the single cpu. >> >>See the problem of the parallel speedup of Hydra? >> >>They can brag whatever about speedup, as long as they aren't comparing an >>optimized single cpu version with the 32 processor version, it's not a very fair >>compare. >> >>You can get a million nodes, but if all what you do with it is search 6 ply in a >>highly selective manner, that still is 6 thin plies. >> >>It isn't 7 ply which i get with perhaps at most 100000 nodes, without any >>forward pruning (just nullmove). Then we didn't discuss the huge evaluation >>difference even. >> >>Rudolf Huber (SOS) calls that: "they first slow it down, or make the branching >>factor horrible, in order to be able to claim a better speedup". >> >>>-Josh > >What kind of interest has the Hydra team of doing that? Anyway, the fact >remains, it blows all PC programs, including Diep, of the board! >Simple or complicated paralell search, null move etc. etc. who cares as long as >it is the strongest chess machine on the planet! > >Torstein No proof for it. It is only an opinion. I believe that Shredder is stronger than Hydra and Shredder was unlucky to suffer from a bug so the version that played hydra was weaker than the commercial version. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.