MPerft

Fast bitboard chess move generation based on magic bitboards, optional bulking or nullmove^newcount, transposition table & multithreading.

Usage:

mperft <args> 
Enumerate moves. The following options are available:
	--bulk|-b               Do fast bulk counting at the last ply.
	--nullmove|-n           Do fast nullmove counting at the penultimate ply.
	[--depth|-d] <depth>    Test up to this depth (default = 6).
	--div                   Print a node count for each move.
	--fast                  Automatically set highest settings.
	--fen|-f <fen>          Use the position indicated in FEN format (default = starting position).
	--hash|-h <size>        Use a hashtable with <size> Megabytes (default = 0, no hashtable).
	--help|-?               Print this message.
	--kiwipete|-k           Use the kiwipete position.
	--moves|-m <moves>      Play a serie of moves to build the position to use.
	--loop|-l               Loop from depth 1 to <depth>.
	--quiet|-q              Disable verbose output.
	--repeat|-r <n>         Repeat the test <n> time (default = 1).
	--seed|-s <seed>        Change the seed of the pseudo move generator to <seed>.
	--test                  Run an internal test to check the move generator.
	--threads|-t <threads>  Use <threads> threads for parallel processing (default = 1).

Limitation:

Mperft is limited to a maximal depth of 64 plies. The hash table is limited to the available memory or 2⁶⁴ bytes. The number of threads is limited to the number of logical cores available. On 64 bits versions, the leaf counter is limited to 2⁵⁸ = 288,230,376,151,711,744 leaves, which is enough for executing mperft up to depth 13. On 128 bits versions, the leaf counter is limited to 2¹²² = 5,316,911,983,139,663,491,615,228,241,121,378,304 leaves.

Binary Release

You can download the binary release for your platform from the releases page. Executable are given for Linux & Windows for intel64/amd64 cpu in 3 flavours:

• x86-64
• x86-64-v2 support AVX extension, including the popcount instruction.
• x86-64-v3 support AVX2 extension, including the PEX instruction.
• x86-64-v3-128 support AVX2 extension, including the PEX instruction and use 128 bits counter & Zobrist's hash keys.

Compilation

You can compile mperft for your own CPU using the makefile or the .bat file provided for clang & icx (intel C compiler). For example under Linux, using the clang compiler:

CC=clang make

or under MS-Windows, after opening a terminal windows:

build-clang.bat native

Example

$ mperft --fast -l 12
Magic Perft version 5.1 (c) Richard Delorme 2020 - 2026
Bitboard move generation based on magic (pext) bitboards.
Perft setting: hashtable size: 32768 Mbytes (2147483652 entries); with 32 threads; with nullmove counting.
  a b c d e f g h
8 r n b q k b n r 8
7 p p p p p p p p 7
6 . . . . . . . . 6
5 . . . . . . . . 5
4 . . . . . . . . 4
3 . . . . . . . . 3
2 P P P P P P P P 2
1 R N B Q K B N R 1
  a b c d e f g h
w, KQkq
perft  1:                         20 positions in           0.000   9.321 Mpos/s
perft  2:                        400 positions in           0.000 167.772 Mpos/s
perft  3:                      8,902 positions in           0.000 352.242 Mpos/s
perft  4:                    197,281 positions in           0.000 910.293 Mpos/s
perft  5:                  4,865,609 positions in           0.000   8.367 Gpos/s
perft  6:                119,060,324 positions in           0.003  30.746 Gpos/s
perft  7:              3,195,901,860 positions in           0.038  83.711 Gpos/s
perft  8:             84,998,978,956 positions in           0.385 220.556 Gpos/s
perft  9:          2,439,530,234,167 positions in           4.564 534.403 Gpos/s
perft 10:         69,352,859,712,417 positions in          48.956   1.417 Tpos/s
perft 11:      2,097,651,003,696,806 positions in       10:45.261   3.251 Tpos/s
perft 12:     62,854,969,236,701,747 positions in     3:36:03.503   4.849 Tpos/s
total   :     65,024,500,949,358,489 positions in     3:47:42.715   4.759 Tpos/s
full time:     3:48:30.456 s
total   :    65024500949358489 leaves in  14714.880 s  4418962235419 leaves/s
full time:  14762.732 s

History

• Version 1.0
• Version 1.1 More compact hash table using bitfields to store the counter & the depth.
• Version 2.0 Use copy/make instead of update/restore after each move. Replace bitfields with shift/mask.
• Version 3.0 Add support for multithreading.
• Version 3.1 Remove some OS/platform dependencies. Alphabetically sort the move with the --div command.
• Version 3.2 Remove more OS/platform dependencies. Fix a bug (free() incompatibility with _aligned_malloc()). Faster executable for Windows.
• Version 4.0 Code fix & optimisation. Add --fast & --moves option. remove --capture option.
• Version 4.1 Code fix & optimisation. Add optionally compiled 128 bit support for crunching big numbers.
• Version 5.0 Add nullmove counting at the penultimate remaining depth (=2). Significantly faster.
• Version 5.1 Add Gigantua's benchmark, more readable output & some small enhancements. Slightly faster.

Performance

Time to compute perft 7 with bulk counting on a ryzen 9 5950x @ 4.2 Ghz under Linux :

Version	Time	Options	Progress
1.1	3.865 s	-b 7
2.0	3.787 s	-b 7	+2.1%
3.2	3.811 s	-b 7	-0.6%
4.1	3.006 s	-b 7	+26.8%
5.0	3.314 s	-b 7	-9.3%
5.0	2.070 s	-n 7	+60.1%
5.1	1.993 s	-n 7	+3.8%

Time to compute perft 8 with bulk counting and 256 MB of hash table:

Version	Time	Options	Progress
1.1	9.985 s	-b 8 -H 24
2.0	9.709 s	-b 8 -h 256	+2.8%
3.2	10.138 s	-b 8 -h 256	-4.2%
4.1	8.420 s	-b 8 -h 256	+20.4%
5.0	6.655 s	-n 8 -h 256	+26.5%
5.1	6.522 s	-n 8 -h 256	+2.0%

Time to compute perft 9 with bulk counting, 32 threads and 1 GB of hash table:

Version	Time	Options	Progress
2.0	118.197 s	-b 9 -h 1024
3.2	6.249 s	-b 9 -t 32 -h 1024	+1791.4%
4.1	5.386 s	-b 9 -t 32 -h 1024	+16.0%
5.0	4.708 s	-n 9 -t 32 -h 1024	+14.4%
5.1	4.422 s	-n 9 -t 32 -h 1024	+5.3%