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Subject: Re: Perft(10) verified

Author: Albert Bertilsson

Date: 07:20:07 12/10/03

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On December 10, 2003 at 07:37:33, Sune Fischer wrote:

>On December 10, 2003 at 07:10:37, Albert Bertilsson wrote:
>>
>>On the 2GHz P4 (not the fastest machine, but the one I use right now) Sharper
>>get 18Mnps. What makes the numbers look so good is of course the usage of hash
>>tables, without them it would be a whole diffrent story.
>>
>>/Regards Albert
>
>Hey Albert congrats, you finally did it! :)
>
>It gave it a go in the summer, but my machine crashed after 20 hours or so, I
>only got the first few sub-results.
>
>But my questions is, since you used different machines haven't you lost most of
>the hashing benefit?

I lose some of the benefits, ideal would be a huge shared memory and multiple
fast processors attached to that memory.

The main problem was divided by doing perft 7 on all perft 3 positions. The
perft 3 position are 8902 and even in them there are some duplicate positions
(around 700) that didn't need any calculation at all.

The fastest machine did perft(9) in 5 hours so I still think that using multiple
machines gave me a considerable net gain in time (5 * 30 = 150 hours). Of course
the really nice thing is that the result of subcalculations are saved to disk,
which will be needed when I go after perft(11) =).

I've always wanted my own distributed project and I think of setting up a server
on the internet when I get internet connection at home.

/Regards Albert
>
>When I try the small perft depth it seems to get quite a lot faster on the last
>moves, example:
>
>-->: perft 7
> a2a4 ~ 137077337 [2.73 secs]
> b2b4 ~ 134087476 [2.55 secs]
> c2c4 ~ 157756443 [2.69 secs]
> d2d4 ~ 269605599 [4.27 secs]
> e2e4 ~ 309478263 [4.63 secs]
> f2f4 ~ 119614841 [1.59 secs]
> g2g4 ~ 130293018 [1.64 secs]
> h2h4 ~ 138495290 [1.59 secs]
> a2a3 ~ 106743106 [1.22 secs]
> b2b3 ~ 133233975 [1.48 secs]
> c2c3 ~ 144074944 [1.52 secs]
> d2d3 ~ 227598692 [2.44 secs]
> e2e3 ~ 306138410 [3.31 secs]
> f2f3 ~ 102021008 [0.64 secs]
> g2g3 ~ 135987651 [0.81 secs]
> h2h3 ~ 106678423 [0.44 secs]
>Nb1a3 ~ 120142144 [0.55 secs]
>Nb1c3 ~ 148527161 [0.59 secs]
>Ng1f3 ~ 147678554 [0.50 secs]
>Ng1h3 ~ 120669525 [0.16 secs]
>perft 7 = 3195901860 [35.34 secs]
>
>-S.



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