What is a good perft speed?

[Ras]

I tried tricks like that but couldn't get any significant nps increase out of it (for search). The one you describe only works when not already in check.

Correct, my approach doesn't work for in-check positions (but I have evasions for that), king moves, and I also exclude en passant moves. Still, I got a measurable speedup, IIRC something like 10% or so. The reason is that my move generator and in-check test work with for-loops (sliders) and dedicated if-checks (knights). If your engine has a more efficient implementation to begin with, the spared work and hence the speed-up will be smaller.

[Ajedrecista]

Hello:

[...]

So I ran benchmarks of Perft(7) of the starting position in my PC with SF 16, qperft, JetChess 1.0.0.0 and gperft 1.1 to compare:

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[...]

=======================================================================
ENGINE / COUNTER        HASH (MB)        THREADS        TIME (M:SS.sss)
=======================================================================
gperft 1.1                 64               2           0:00.815
gperft 1.1                 64               2           0:00.866
[...]

[...]

There is a typo at the top of the chart that I want to correct:

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[...]

=======================================================================
ENGINE / COUNTER        HASH (MB)        THREADS        TIME (M:SS.sss)
=======================================================================
gperft 1.1                 64               2           0:00.815
gperft 1.1                128               2           0:00.866
[...]

I wrongly duplicated 64 MB of hash when writting.

Regards from Spain.

Ajedrecista.

[eduherminio]

I've updated the list
https://github.com/FireFather/perft-speeds

Now it's an editable table instead of a bitmap.

I'll be happy to add engines...
just contact me here firefather at telenet dot be
and send a copy of or point me to your engine.

Isn't the used fen/position quite a relevant piece of information to include?

[chessbit]

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$ time ./main divide startpos 7                                                                                                                        
... moves ...
perft 3195901860 nps 639087301 time 5.000728

real    0m5.003s
user    0m5.003s
sys     0m0.000s

This is pretty good. Could you tell us what approach you used? I assume bitboards, perhaps with pext?
Did you move some logic to compile time?
My engine is about 50% slower with only run time but I don't find many ways to improve

[mvanthoor]

639 million NPS... that's a lot. I assume you use bulk counting and/or a transposition table, and maybe other perft-specific tricks.

My engine runs at +/- 58 million NPS, on a Ryzen 7950X, without a hash table, multi-threading or bulk counting. On an older i7 6700K, it runs at 32 million NPS. It does full incremental updates for its evaluation and Zobrist key when running perft; I do not disable this (because I mainly use perft to see if everything is working as it should.)

When running with a hash-table, speed increases the deeper it goes (obviously, because more and more depths can be pulled directly from the TT):

With 256 MB TT:

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Perft 1: 20 (0 ms, inf leaves/sec, hash full: 0%)
Perft 2: 400 (0 ms, inf leaves/sec, hash full: 0%)
Perft 3: 8902 (0 ms, inf leaves/sec, hash full: 0%)
Perft 4: 197281 (3 ms, 65760333 leaves/sec, hash full: 0%)
Perft 5: 4865609 (58 ms, 83889810 leaves/sec, hash full: 1%)
Perft 6: 119060324 (819 ms, 145372800 leaves/sec, hash full: 13.3%)
Perft 7: 3195901860 (10874 ms, 293903058 leaves/sec, hash full: 90.3%)
Total time spent: 11754 ms
Execution speed: 282459962 leaves/second

Average at 282 million NPS/second, but because this will keep increasing, I doubt it actually says anything. Someday I'd have to make this multi-threaded to see how fast it will go. I did an experiment a few years ago when just developing the engine, and it worked, but it wasn't the best way of multi-threading perft.