search speed

[elcabesa]

writing my own c# chess engine I'm now trying to speed it up.

my program is written in c#, can't use any assembler optimization( pospolation count etc) , is 32bit, use bitboard, no magicbitboard, no hashtable, lookuptable for knight & king, shift for pawns.


on my 2 years old pc my perft function can run at 1.2 Mnodes/s

I need to define a target speed to reach

can you point me to engines with perft function I can test? i need some good engine that can be run without asm optimization and with has table disabled.
It doesn't need to be a c# program

thank you

[mathmoi]

You could try Sharper it's an engine written in C#. It was used a couple years ago to compute the value of perft(11) from the start position.

[vladstamate]

Hi,

Few things you want to be careful about when measuring your speed against other programs that can do perft are:

1) Are you making and unmaking leaf nodes too? Most of the programs do, since it makes sense, you really want to see the speed of make/unmake.
2) Are you using hashing/caching/transposition tables or anything that would stop you from actually making/unmaking ALL (legal) moves?

Regards,
Vlad.

[elcabesa]

1) i only make domove and don't do unmake, a game is an array of position so unmake move is somethink like "index--;"
2) my code doesn't have any kind of hashin/caching/transposition till now


sharper is a very very fast c++ cengine

[phhnguyen]

1) i only make domove and don't do unmake, a game is an array of position so unmake move is somethink like "index--;"

I guess that he means the method of implementation of perft, not only do/unmake. There are two ways, very little different in implementation but may give a difference on speed:

if (depth == 0) return 1;
n_moves = GenerateMoves(move_list);

vs

n_moves = GenerateMoves(move_list);
if (depth == 1) return n_moves;

Take a look at documentation: http://chessprogramming.wikispaces.com/Perft

2) my code doesn't have any kind of hashin/caching/transposition till now


sharper is a very very fast c++ cengine

[elcabesa]

it's a

Code: Select all

if(depth==0) return 1;

program.

i know the other one is faster, but I think i implemented it this way to get a legal move generator.
Maybe it's possible to implement it the other way

[Sven]

it's a

Code: Select all

if(depth==0) return 1;

program.

i know the other one is faster, but I think i implemented it this way to get a legal move generator.
Maybe it's possible to implement it the other way

I think it's the other way round. You can only do "return n_moves" after move generation at depth 1 if you have a fully legal move generator, while the "if (depth == 0) return 1" approach allows for a pseudo-legal move generator if you immediately unmake illegal moves.

Sven