Search found 171 matches

by Sesse
Wed Jun 12, 2019 4:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: strategies for finding slowdows in lazy smp
Replies: 26
Views: 1020

Re: strategies for finding slowdows in lazy smp

jdart wrote:
Tue Jun 04, 2019 10:20 pm
A profiler might also be helpful. You could try OProfile for Linux (http://oprofile.sourceforge.net/news/).
oprofile? Is this 1999? :-)

perf is really what you want these days; it has basically all the mindshare. If you want something more GUI-ish and commercial, there's stuff like VTune.
by Sesse
Fri Apr 26, 2019 8:55 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Prefetch and Threading
Replies: 4
Views: 476

Re: Prefetch and Threading

I tried prefetch for TT in Stockfish at some point, and couldn't measure a gain. As you say, the prefetch is really only effective if you can issue the prefetch some time before the actual access.
by Sesse
Fri Apr 05, 2019 3:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Elo World, a framework forbenchmarking weak chess engines
Replies: 8
Views: 1792

Re: Elo World, a framework forbenchmarking weak chess engines

It is a joke you guys. If it helps, read the last page: "The author would also like to thank the anonymous referees of the Special Interest Group on Bafflingly Overdone Ventures In Chess journal for their careful reviews." It's a SIGBOVIK paper; SIGBOVIK is a joke conference. But Tom7 frequently su...
by Sesse
Wed Jan 30, 2019 11:50 pm
Forum: Computer Chess Club: Tournaments and Matches
Topic: How powerful is the Queen compared to 2 Rooks ?
Replies: 104
Views: 5488

Re: How powerful is the Queen compared to 2 Rooks ?

Here is what Stockfish says about the value of chessmen (note that pawns are not 100) during the midgame and during the endgame: PawnValueMg = 136, PawnValueEg = 208, KnightValueMg = 782, KnightValueEg = 865, BishopValueMg = 830, BishopValueEg = 918, RookValueMg = 1289, RookValueEg = 1378, QueenVal...
by Sesse
Sat Jan 26, 2019 10:44 am
Forum: Computer Chess Club: General Topics
Topic: Big boost in strength for LC0 by simply changing VGA card
Replies: 19
Views: 2284

Re: Big boost in strength for LC0 by simply changing VGA card

The RTX 2000 series has specialized hardware for neural networks. These “tensor cores” is the reason why your new GPU blows the old one out of the water—the number of CUDA cores simply doesn't matter, as they're not the ones doing the work.
by Sesse
Wed Jan 23, 2019 11:02 pm
Forum: Computer Chess Club: General Topics
Topic: Are computes without Database endgame better than Carlsen?
Replies: 9
Views: 1163

Re: Are computes without Database endgame better than Carlsen?

I think it depends on your definition of “better”. I'm fairly certain Stockfish on a fast computer would have a positive endgame score versus Carlsen. I'm not convinced it's as good as him in swindling drawn endgames against other GMs. A computer doesn't really understand the concept of putting the ...
by Sesse
Sun Jan 13, 2019 11:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Writing bugs
Replies: 66
Views: 7867

Re: Writing bugs

State is fine but it should be encapsulated in an object. Like so: rg=random_generator(seed) r=rg.rand() The state maintained by the rg object could be much more complicated than a single number (this would likely be the case for a cryptographically secure random generator). The rg object completel...
by Sesse
Sun Jan 06, 2019 8:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Writing bugs
Replies: 66
Views: 7867

Re: Writing bugs

Rebel wrote:
Sun Jan 06, 2019 4:09 pm
Today I had a new one, took me hours to see it.
Why didn't your compiler warn you?
by Sesse
Fri Jan 04, 2019 9:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Can you improve CPU performance with Intel library?
Replies: 4
Views: 652

Re: Can you improve CPU performance with Intel library?

It depends on what calculations you are doing. If you want to speed up big matrix multiplications, FFTs or other numerical code (and you don't want to push it to the GPU), MKL can help you. But an alpha-beta chess engine does none of that. NN engines do big matrix multiplications and convoltions, bu...
by Sesse
Thu Dec 20, 2018 12:22 am
Forum: Computer Chess Club: General Topics
Topic: 7 Man Syzygy and SSD
Replies: 27
Views: 2729

Re: 7 Man Syzygy and SSD **Hashes**

I don't seem to be able to find a list of MD5 hashes for 7 piece tables. I'd like to verify my downloads are not corrupt. Could someone point me to a list of hashes? Thanks Mike No MD5, but something better: http://tablebase.sesse.net/syzygy/7-DTZ/SHA256SUMS http://tablebase.sesse.net/syzygy/7-DTZ/...