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Subject: Re: What is meant by NPS?

Author: Vincent Diepeveen

Date: 03:38:36 08/09/99

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On August 09, 1999 at 02:41:45, david burrell wrote:

NPS is in my program and crafty the summation of the number of calls to
the bruteforce part and the quiescencesearch.

So in fact it's the number of makemoves minus current iteration depth.

>There is a huge variation between the NPS reported by a variety of
>chess software. I realize that there are many factors that might
>effect NPS like move-ordering, complexity of static eval, hashing etc.
>but perhaps not all chess programs count the same thing.
>
>So what do you define NPS as? I would count calls to make-move. This is
>what my program does. I have heard that some people count total nodes
>generated by movgen and others count only leaf nodes.
>
>I am concerned that my program is very slow, about 15K NPS in opening
>positions on a P200, (crafy reports about 50K NPS). How does crafty
>count NPS?

>If the LG2000 winboard engine has peaked at over 1M NPS on a K6-2/450
>then surely LG2000 is not counting calls to make-move 1M is very high!!
>
>Any comments would be greatly appreciated. Thanks.
>
>David.

Yeah initially your datastructure is very slow. Compare this speed:
after 1.e4,e5 2.d4,d5 you just do 10 million generateallsemilegalmoves();

Now you multiply 10M by the number of semilegal moves and divide by
the number of milliseconds needed. Then you get a count for how
fast your generation is. I'm talking about full generation of course.

DIEP can generate 15.5M nodes a second here at a PII450.
So far i didn't hear someone
faster in C than this number.

Suppose my program would be quite stupid, then i could get of course a huge
speed. I mean i can generate 15.5M!

a simple Makemove goes at similar speed. So the most dumb program could
be searching at many million nodes a second!

For example: Junior here gets around 400k nodes a second in C++!
Fritz gets 500k nodes a second in assembler.

Of course their extra speed is because they don't generate full move
lists. they just generate for a piece a few moves. Then pick the next
piece and so on.

Vincent





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