Search found 16793 matches

by bob
Fri May 04, 2007 7:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22614

Re: Interesting position from Jouni Uski

you need to figure out why Crafty failed the test, when it works perfectly for any version I tried... There is definitely an interface or operator issue involved here. At the time I did a quick test with Crafty on Mac OS X (it was version 19.13 IIRC, downloaded with Fink), just open a terminal, run...
by bob
Fri May 04, 2007 3:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22614

Re: Interesting position from Jouni Uski

you need to figure out why Crafty failed the test, when it works perfectly for any version I tried... There is definitely an interface or operator issue involved here.
by bob
Fri May 04, 2007 3:09 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22614

Re: Interesting position from Jouni Uski

Crafty sees this just fine: White(1): move time surplus 0.00 time limit 22.50 (+0.00) (3:30) depth time score variation (1) 1 0.00 -2.24 1. Rxd4 1 0.00 Mate 1. dxe6# 1-> 0.00 Mate 1. dxe6# 2 0.00 Mate 1. dxe6# 2-> 0.00 Mate 1. dxe6# 3 0.00 Mate 1. dxe6# 3-> 0.00 Mate 1. d...
by bob
Tue May 01, 2007 9:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Checks and move ordering
Replies: 11
Views: 11057

Re: Checks and move ordering

I have been working on my move generator and now I know if a move gives check before I make it. Now I am wondering how I should use this information in move ordering, e.g. should a winning capture that gives check be tried ahead of winning captures that appear to gain more material, or should disco...
by bob
Tue May 01, 2007 9:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 35659

Re: Speedup with bitboards on 64-bit CPUs

Yes, I noticed that the term 'mailbox' is used in different ways. In TSCP it means something very strange, and I was never able to figure out what. Most people seem to use it for an array-based representation that has a guard-band around the board of immovable uncapturable pieces, so that no specia...
by bob
Tue May 01, 2007 9:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 35659

Re: Speedup with bitboards on 64-bit CPUs

I'm confused. 0x88 _is_ a "mailbox" approach. The term "mailbox" comes from treating an array like a series of mailboxes, each element has a unique address. Any array-based approach that uses one array element per board square is a "mailbox implementation". In TSCP the actual board is a 64 element ...
by bob
Mon Apr 30, 2007 8:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 35659

Re: Speedup with bitboards on 64-bit CPUs

This strikes a cord. I was writing a new 0x88 program for the Palm z22 I bought recently, but it was just too slow (on the pc) so I have gone back to bitboards mainly because this is the way I think. Eval on 0x88 was so hard. I guess it is familiarity that matters. There seems no intrinsic reason w...
by bob
Mon Apr 30, 2007 5:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 35659

Re: Speedup with bitboards on 64-bit CPUs

I suspect you just need some "seat time" to get acclimated. I've had plenty of seat time by now. In fact, I have almost certainly spent more time on the bitboard version than on the mailbox version of Glaurung 2, and the mailbox version is beginning to lag behind. "scanning for attacks" is a bad id...
by bob
Mon Apr 30, 2007 12:41 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 35659

Re: Speedup with bitboards on 64-bit CPUs

Arasan uses bitboards extensively (including rotated). The 64-bit version is faster but not by much (10-25%). I am not sure why. --Jon Rotated bitboards use lots and lots of multidimentional look-ups which is great for 32 bit processors, because it keeps 64 bit access to a minimum. However, when co...
by bob
Mon Apr 30, 2007 12:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Why is Core 2 Duo prefered for chess programming?
Replies: 11
Views: 10763

Re: Why is Core 2 Duo prefered for chess programming?

A single core-2 processor (just one CPU) is more than twice as fast as a single PIV 2.8ghz xeon. My office machine using both cpus hits 1.5-2.0M nps. My 2.0ghz core-2 laptop hits 5-6M nps. the comparison is startling... Note that the xeon box in my office is 32 bit, while my core-2 is 64 bit and I'm...