Author: Vincent Diepeveen
Date: 14:35:01 07/29/03
Go up one level in this thread
On July 29, 2003 at 17:14:52, Keith Evans wrote: >On July 29, 2003 at 17:04:44, Vincent Diepeveen wrote: > >>On July 29, 2003 at 16:13:19, Keith Evans wrote: >> >>>On July 29, 2003 at 16:00:20, Tord Romstad wrote: >>> >>>>On July 29, 2003 at 12:49:49, Keith Evans wrote: >>>> >>>>>You're perft performance seems pretty decent to me. >>>> >>>>Indeed. I just did a similar test with my own program on a Pentium 4 2.4 GHz. >>>>In the position after 1. e4 e5 2. d4 d5, my program generates 30 million moves >>>>per second. I guess I could speed it up somewhat, but I don't think I would >>>>come anywhere close to the speeds reported by Vincent and Angrim. >>>> >>>>My move genererator assigns all moves a move ordering score, and also >>>>determines which moves are checks. It generates legal moves only. >>>> >>>>But anyway, I don't understand why people spend so much time and energy on >>>>micro-optimising their move generators. Despite my slow movegen speed, my >>>>program spends only 1 or 2 percent of its time in the move generator. I >>>>guess most other programmers have similar numbers. >>>> >>>>Tord >>> >>>I'm personally interested in the performance of the move generator in a hardware >>>chess chip where it is a large percentage of the total cycles. If it were only >>>1-2% of the time then I wouldn't be interested. Of course a hardware move >>>generator can generate millions of NPS when only running at say 30 MHz, so it's >>>a totally different animal than a software generator running on a 3 GHz >>>processor. >> >>hardware doesn't work like that. you cannot store the moves. >> > >Huh? (Duh?) Where did I say that it pregenerates and stores the moves? Of course >it generates them incrementally. but i hope you realize how hard it is to order moves when all you have is 1 bound that gives how far the incremental generation is. but if you compare speeds. Say that each move costs 1 clock. that's 30 million moves a second at 30Mhz right? Brutus ran at 2002 WCC at something like 33Mhz. So that's 33 MLN a second. DIEP i generate way more than 33MLN a second at the 1.6Ghz K7 i had back then. At 2.127Ghz it is about 72MLN. this with slow RAM storage. It's probably relatively faster at a P4 generating moves because of the fast L1 cache there and everything runs within trace cache when doing a loop for a few millions of times. So as soon as we touch the sequential part, then hardware chessprograms look in advance outdated of course. Most people do not realize that though. >And of course when it makes a move it does >store the move so that unmake it later.
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