Crafty problem with cutechess-cli

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

bob
Posts: 20943
Joined: Mon Feb 27, 2006 7:30 pm
Location: Birmingham, AL

Re: Crafty ignores "log off"

Post by bob »

hgm wrote:
bob wrote:I do claim that by using -xreuse, you will _never_ have a problem with Crafty in any game. It won't crash. It won't create log.nnn files if you tell it not to. It just runs solidly each and every game.
You will _always_ have the problem that is slows you down by having to re-load all the time...

Of course when you don't run Crafty at all, you will really _never_ have any problems with it. But is that really a virtue?
I can't measure the startup time for Crafty on my cluster. It is close enough to instant to be called zero. If you use endgame tables on slow drives, it will definitely go up. I test without EGTBs and simply don't see the problem. My reason for using -xreuse is that I have, in the past, had an occasional "wild store" bug. And once a wild-store happens, something is broken. In my case it was a rotated bitboard value. And once that value was broken, the move generator would not work for that specific value. For any future games.

Running most tests with -xreuse prevents that. An occasional test without the -xreuse will show whether the "new" game stuff is working of if something has become corrupted, since the results will change when they should not.

However, if you are using a machine where the "reload time" is significant, you need a better machine. On my machine the initialization takes less than 1/10th of a second (no EGTBs) so unless you are playing game in one second, that's irrelevant. At game in one minute, you need to play 1200 games before you use enough time that you could have played 1201 without the initialization costs.