Author: Dann Corbit
Date: 07:10:20 06/02/04
Go up one level in this thread
On May 29, 2004 at 04:00:31, Gian-Carlo Pascutto wrote: >On May 28, 2004 at 21:27:16, Dann Corbit wrote: > >>I am guessing that the latest professional programs are not NUMA ready yet, >>though probably Deep Sjeng is. > >The Opteron doesn't really need NUMA code for 4 way, although it may start >to be an issue for 8 way. > >There are a few pitfalls, which Crafty was having issues with, but they are >not hard to fix, and the top pro's don't seem the have them. See my tests at >Graz with my machine there that I posted here - all of them scaled excellent. > >(including Deep Sjeng obviously :) > >>The faster the hardware, the better crafty does. I think (compared to others) >>crafty scales better. That would indicate better algorithms and inferior >>microoptimization. Also, the other deep programs do not seem to benefit nearly >>so much from multiple CPUs (though they may have possibly ironed this out). > >I have certainly seen no evidence for that - see my tests with them. > >>On the other hand, I suspect that if Deep Sjeng got the same 8 CPU machine, then >>it would win. > >I don't think so. The program still has weaknesses that a bit of >extra hardware will not overcome. > >>What sort of hardware are you bringing to the party? > >Uh, the provideed P4 2.8Ghz or maybe my Athlon64 2.2Ghz. > >>Now, Shredder Fritz and Junior might come on powerful hardware (e.g. 2.4 GHz AMD >>64 bit dual) but I am guessing that would translate to about 3 GHz throughput. >>[All the measurements I have seen showed them scaling very poorly] > >Again, I cannot confirm that at all! Also, both Junior and Fritz were >already 4 way last year. > >>Crafty -125 Elo (Crafty 19.12 and 19.13 are huge improvements on the >>predecessors) > >Crafty 18.12 is about 200 ELO worse than Shredder 8 - I wonder if >there has been that much improvement in Crafty. > >>So Crafty would have to overcome about 175 Elo to be evenly matched against >>Shredder in my crude model. So, with an 8-way box he would have about >>.65*2.4*8=12.5 GHz (let's say 12). That would be about 4 times faster than >>Shredder, Fritz or Junior. With +70 Elo per doubling, that would be 140 Elo. >>So crafty would have a real shot at it, even against Shredder. > >These maths seem rather flakey. First of all, 8 way does not mean 8 times >faster. A good estimate is a speedup of 6 on an 8 way machine, and quite >possibly less. I assumed a bit less than 65% of each CPU would be the final throughput achieved. >Also, the SSDF has less than 70 ELO for a tripling of speed >nowadays, so 70 for a doubling is also way too high. Crafty seems to get an extra bonus from 64 bit math, though. >Anyway, I'm happy that at least someone is reasoning about this. I think >if you redo the math with the adjusted estimations, and compute the chance >for Crafty to win the event, it'll most likely be 'statistically >insignificant' :) And so it will be for Sjeng. Then you can understand >where my 'claims' are coming from. With just a handful of games, none of the competitors is chanceless.
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