Author: Robert Hyatt
Date: 17:31:41 06/04/02
Go up one level in this thread
On June 04, 2002 at 18:01:03, Gian-Carlo Pascutto wrote: >On June 04, 2002 at 17:52:47, Dann Corbit wrote: > >>On June 04, 2002 at 16:28:39, Gian-Carlo Pascutto wrote: >> >>>On June 04, 2002 at 16:18:55, Gian-Carlo Pascutto wrote: >>> >>>>Because you are using a processor that is clocked at twice the clock >>>>frequency? Why compare a 1ghz processor to a (nearly) 2ghz processor >>>>and conclude anything about efficiency there? Is there anything that >>>>suggests that the alpha is simply more "efficient"? To justify that >>>>clock frequency disparity? >>>> >>>>A machine twice as fast (clock freq) _should_ perform just as well as >>>>a 64 bit machine at 1/2 the frequency... Less would suggest that the >>>>32 bit machine simply sucks badly. >>> >>>I don't agree with the validity of a clock-for-clock comparison, >>>but if you want to do it anyway, I'll again point to Vincent's >>>numbers: >>> >>>At the same clockspeed, Crafty only gets 33% faster on the 64-bits >>>machine. >>> >>>When you read this, keep in mind that most applications get _more_ >>>than 33% faster on the 64-bits machine. >> >>All the new 64 bit chips in the discussion are pretty much beta stage right >>now. > >Not true for the Alpha. Depends on the alpha being discussed. DEC had processors beyond the 21264 running. Although the 21264 was pretty good. Dann was a bit off on the performance as Tim Mann was running a 21264 at 600mhz and getting right at 1M nodes per second. Mckinley is getting 1.5M at 1000mhz, so the alpha might have a bit of an advantage still. but it is pretty small... Mckinley is only available to a select few. 21264's are fairly common. Anything beyond that is not readily available... > >>So, I think that architecturally, it makes good sense to design for a 64 bit >>system right now. > >That makes sense, if the 64 bit design is actually faster than the corresponding >32 bit design (even on 64 bit hardware if you wish). > >The case for bitboards is not clear on that matter. Certainly, if >the speedup over nonbitboards is only 33% they will have a hard time >convincingly beating alternative appraoches even on 64 bit hardware. > >-- >GCP You are assuming that bitboards are _slower_ than non-bitboard programs on 32 bit machines. I haven't seen this demonstrated yet. We can always do some sort of a test. IE since the most common move generator issue is "generate all captures" we can try that with bitboard and non-bitboard approaches to see if one is really much better than the other on 32 bit machines. I don't think so myself. I think they are pretty equal due to the multiple pipe issue. But a test could be done to see, since this is the most common thing needed in a chess engine.
This page took 0.01 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.