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official-stockfish / Stockfish

A free and strong UCI chess engine
https://stockfishchess.org/
GNU General Public License v3.0
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Slowish start on the big core counts #1967

Closed Vizvezdenec closed 5 years ago

Vizvezdenec commented 5 years ago

Just witnessing pretty signifficant slowdown at start of the game at 4c which uses 90 cores and fast TC. https://www.chess.com/computer-chess-championship Click at any game/speed, sf at first move hovers between 1/4 and 1/2 of normal 90~ mnps there (sometimes for 1-2 moves extra). Also I've seen some graphs from people tests showing the same https://i.postimg.cc/GtY4vf3m/Screenshot-96.png and this thing is not existing in cfish/asmfish.

JavaMast commented 5 years ago

@Vizvezdenec
In my case it is because of a big hash. Same thing happens in command prompt.

bench 16384 8 15

screenshot_109 screenshot_107

On 1 core:

screenshot_111

In Aquarium GUI, Stockfish needs about 5-6 seconds before start thinking. But speed is normal, no drop.

=============== CPU Ryzen 1700X

CoffeeOne commented 5 years ago

@Vizvezdenec Yes, asmfish and cfish use large pages under Windows, original stockfish not. So stockfish has a (big) slowdown with this high TT size. For short time control 16GB does not make sense. Or switch to Linux, then there is no problem :)

JavaMast commented 5 years ago

@CoffeeOne On my PC Large Pages is disabled in OS

======= I had to add: speed is increases on higher depth screenshot_113

Vizvezdenec commented 5 years ago

@CoffeeOne 4c uses linux. Sf is still slowed down on 1st move there.

d3vv commented 5 years ago

and very slow random for hash, need xoshiro or jenkins's prng )))