Author: Vincent Diepeveen
Date: 04:21:29 09/25/01
Go up one level in this thread
On September 25, 2001 at 00:38:36, Robert Hyatt wrote: >On September 24, 2001 at 22:30:26, Vincent Diepeveen wrote: > >>Hello, >> >>Here written down speedups as claimed by a guy called R. Hyatt >>by cray blitz for 24 different positoins as they occured in >>a game: >> >>pos speedup >>1 2.0 >>2 2.0 >>3 2.0 >>4 2.0 >>5 2.0 >>6 2.0 >>7 1.9 >>8 2.0 >>9 2.0 >>10 2.0 >>11 2.0 >>12 1.9 >>13 1.9 >>14 2.0 >>15 2.0 >>16 1.9 >>17 1.7 >>18 1.8 >>19 2.0 >>20 2.0 >>21 2.0 >>22 1.9 >>23 2.0 >>24 2.0 >>avg 2.0 > >Please re-do your math. No way to average 2.0 with even _one_ value that >is < 2.0 > >There are several above that are less than 2.0 Page 16 at ICCA journal March 1997 you claim Average for 2 processors 2.0 >>So YOU, Robert Hyatt, claims in an OFFICIAL magazine, >>called ICCA journal march 1997, >>an AVERAGE speedup of 2.0 with cray blitz at 2 processors. >> > >I don't see an average of 2.0... > > > >>Now i claim the same with DIEP if i'm not using dangerous >>extensions (which btw are turned on by default). > >No... You claim > 2.0 which is not possible over a set of positions. Unless >your sequential search is simply badly flawed. Then it doesn't matter. Go get >a copy of my Ph.D. dissertation. I proved quite clearly that for a minimax >search (alpha/beta with worst-possible ordering) it is possible to get a >near-perfect speedup curve. I also proved that with perfect ordering, the >same is possible. But The real point was that I clearly proved that we can't >get perfect move ordering (for obvious reasons) so that for normal cases, an >optimal (4.0 using 4 cpus) is not possible. The only time when i got close to 4.0 at 4 processors was when i forward pruned in a very dubious way. That was at world champs. Nowadays versions i'm pretty sure i'm not even close to the 3.7 which you had with Cray Blitz. Of course at the Quad i only ran with versions which have turned on dubious extensions by default. I have no idea what a run longer than say 10 minutes gives for kind of speedup, but i can imagine very well that because of reasons written down here, that it won't be good. For parallellism, running on 2 processors is perfect! > > > > >> >>It appears you hadn't turned them on either (smart guy >>to publish only speedups without dangerous extensions and only >>tell in 2001 that you hadn't turned them on). > >I was supposed to tell I hadn't turned on something I was not using because >it caused a serious problem??? I don't follow that logic. And I don't consider >the SE as "a dangerous extension". I don't do "dangerous extensions" anywhere >in my code, either now or then...
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