Author: Vincent Diepeveen
Date: 17:57:14 06/06/02
Go up one level in this thread
On June 06, 2002 at 20:35:03, Robert Hyatt wrote: I wrote 20 pages of explanation with examples what is completely impossible to do in bitboards very fast in my evaluation, about a year ago (bit less). Then you said: "well i don't need that info for my evaluation, so bitboards is ok for me". That's a choice you make. But please don't do as if you have forgotten again those 20 pages. If you don't need a better evaluation, but only a very elementary basic bean counter evaluation, then that's your choice. My choice is doing more in evaluation, and i can't use bitboards for that. Best regards, Vincent >On June 06, 2002 at 19:47:14, Vincent Diepeveen wrote: > >>On June 06, 2002 at 10:25:25, Robert Hyatt wrote: >> >>>On June 05, 2002 at 17:31:45, Gerd Isenberg wrote: >>> >>>>On June 05, 2002 at 13:22:30, Vincent Diepeveen wrote: >>>> >>>>>On June 05, 2002 at 04:14:41, Gerd Isenberg wrote: >>>>> >>>>>Gerd, a 33% speedup isn't much if you first slow down 2 times. >>>>>Right now the crafty datastructure is exactly 2 times slower doing >>>>>what i can do without bitboards. >>>>> >>>> >>>>Vincent, if, as you claim, bitboarders are two times slower per se on 32bit >>>>hardware, then i expect a speedup of >= 100% with bitboards on 64bit hardware. >>>> >>>>Gerd >>> >>> >>>This argument goes in circles, because he also claims they are not very >>>good on 64 bit machines either... >> >>Not really. the problem is the bitboarders have a different goal it seems. >>If all you want is a Sum(squaresattacked) as mobility function, then sure >>bitboards are an interesting thing to use at 64 bits processors. If you want >>more, then bad luck with bitboards. Factor 2 slower. > >based on what? Your lack of experience with them or proof that there are >some things that bitboards can't do? I know the latter is not true... > >Why do you want to waste so much time trying to explain why this approach >is bad, when you have not tried it yourself. It takes time to get used to >it. once you do, you discover that a lot of those "problems" are imaginary >only. > > > >> >>At 64 bits processors 33% faster, still like 1.6 times slower. >> >>Best regards, >>Vincent > > >Again, what single cpu machine at 1ghz can run crafty at 1.5 M nodes per >second? Absolutely none unless we go to a Cray. Or a Mckinley 64 bit >processor...
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