Author: Robert Hyatt
Date: 05:17:59 10/22/98
Go up one level in this thread
On October 22, 1998 at 01:12:46, Kai Skibbe wrote: >On October 21, 1998 at 11:08:15, James Robertson wrote: > >>On October 21, 1998 at 10:54:16, James T. Walker wrote: >> >>>If I understood a previous thread, Dr. Hyatt indicated that there is >effectively >>>no move ordering done by most programs(At least Crafty)? >> >>Crafty orderes moves by firstly trying the hash move, then killers? (I'm not >>sure), then gainful captures, etc. There is actually a lot of move ordering >>done, but for Crafty, it is all in *generating* more promising moves first. My >>program has very primitive move ordering, using only pv search, gainful >>captures, and killer moves. Each one of these heuristics has reduced move time >>by 25% to 50%, so obviously move ordering is really important. I plan to add >>hash, history (this will profoundly rearrange your move list), and other stuff >>as soon as I find out I failed biology, and say "the heck with it. Might as well >>work on my program!" :) >> >>>Can anyone please >>>answer this for me?? It seems unreal that there would be no attempt to order >>>the moves so that the most promising moves were searched first. >>> >>>Another question-- Can anyone tell me if there is any advantage to having 1 meg >>>of L2 cache vs 512K relative to chess programs? > >Hi Jim, > >the speed difference will be minimal, but with most motherboards the cacheable >area with 1MB L2Cache is twice as with 512KCache. So I think 1M L2 Cache is >worth the extra money. >For example I have the NMC 5VMMX with 1MB Cache and the cacheable area is 256MB >RAM. With only 512KB Cache the cacheable area would be only 128MB RAM. > > >Best Regards >Kai > This isn't always true. IE the PII's (anything 300mhz and up at least) can cache the full 32 gigs of main memory, if you can afford it. The size of cache should have no effect on how much memory can be cached. It depends on the design of the cache and the size of the tag ram used for verifying cache hits. However, I haven't seen any designs where doubling cache doubles the amount of cacheable RAM... because the size of the cache is usually a jumper on motherboards. There were some few pentiums and pentium II's that could only cache the first 64MB... but for any pentium II, external cache doesn't exist, so we are talking about regular pentiums or clones I assume, since the pro's and II's have the L2 cache internal... > >> >>I haven't a clue! >> >>>Thanks,\ >>>Jim Walker >> >>Hope I helped, >>James
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