Search found 16764 matches

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: 10492

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...
by bob
Sun Apr 29, 2007 12:48 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Splits per Second? -- Bob?
Replies: 4
Views: 4983

Re: Splits per Second? -- Bob?

Maybe Bob is the best to answer this? On a 4 processor and an 8 processor machine. How many splits per second is averaged on a 3 minute search and a 30 second search? In other words, how many forks are done in an MP implementation or how many threads are used/called in a threaded implementation. pr...
by bob
Sun Apr 29, 2007 12:38 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 34894

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
Sun Apr 29, 2007 12:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 34894

Re: Speedup with bitboards on 64-bit CPUs

I would not expect any speedup from bitboards compaired to mailbox, even in 64-bit mode, if you jsut use them to replace the move generator. For bulk move generation bitboards cannot beat mailbox. They are very much faster than mailbox for generating moves selectively (e.g. only captures, only chec...
by bob
Sun Apr 29, 2007 12:32 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Why is Core 2 Duo prefered for chess programming?
Replies: 11
Views: 10492

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

It is simply faster in every test I have run. faster in 64 bits. Faster in 32 bits. Faster everywhere. Bigger cache. Just the best there is right now...
by bob
Thu Apr 26, 2007 4:37 pm
Forum: Computer Chess Club: General Topics
Topic: How long before engine see this as draw
Replies: 5
Views: 2434

Re: How long before engine see this as draw

One second here... 20-> 0.82 -0.61 1. Kf4 Kc7 2. Ke5 Kd8 3. Kd6 Ke8 4. c3 Kf7 5. Kxd7 Kf6 6. Kxc6 Kxf5 7. Kd5 g5 8. c4 g4 9. c5 g3 10. c6 g2 21 0.87 +1 1. Kf4!! 21 0.93 0.01 1. Kf4 Kc7 2. Ke5 Kd8 3. Kd6 Ke8 4. c3 Kf7 5. Kxd7 Kf6 6. Kxc6 Kxf5 7. Kd5 g5 8. c4 g4 9. c5 g3 10. c6 g2 11. c7 g1=Q 12. c8=Q...
by bob
Thu Apr 26, 2007 4:20 pm
Forum: Computer Chess Club: General Topics
Topic: Eigenmann Endgame Test: Deep Sjeng, Crafty, Nimzo a.o.
Replies: 4
Views: 2117

Re: Eigenmann Endgame Test: Deep Sjeng, Crafty, Nimzo a.o.

can you tell me what hardware you are using? I have posted this previously, but again, running on my dual-core 2.0ghz core-2 laptop, I get this using no endgame tables: total positions searched.......... 100 number right...................... 73 number wrong...................... 27 percentage right...
by bob
Wed Apr 25, 2007 7:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Compiling Crafty
Replies: 21
Views: 9350

Re: Compiling Crafty

Then something is broken. Unitialized global variables are supposed to be initialized to zero automatically. What compiler are you using??? I'll make sure everything in "shared" is initialized, but that should already be done.
by bob
Sat Apr 21, 2007 9:51 pm
Forum: Computer Chess Club: General Topics
Topic: hard position
Replies: 10
Views: 5420

Re: hard position

Dann, you are confounding my poor brain. :D You and Robert Yatt said that the best move is anyone that wins the game, and Qxg7 wins. Paulo Soares Two different issues. For any given position, I believe that any move that wins the game is a "best move". But for a test position, it is far better if i...
by bob
Tue Apr 17, 2007 6:37 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material imbalance evaluation
Replies: 10
Views: 12892

Re: Material imbalance evaluation

Thanks Mark, it seems SCID will do the work just fine! :-) I completely agree. You need a _random_ same of games played where N for PP trade occurred. Not just a sample of games humans played where the players were good and they only played the sac when they had a strong positional edge after doing...