Author: Robert Hyatt
Date: 08:19:01 06/13/99
Go up one level in this thread
On June 13, 1999 at 09:25:30, James T. Walker wrote: >On June 13, 1999 at 00:44:04, Robert Hyatt wrote: > >>On June 12, 1999 at 21:53:27, Brett Clark wrote: >> >>>On June 12, 1999 at 21:30:05, Robert Hyatt wrote: >>> >>>>On June 12, 1999 at 17:24:15, Gustavo Pereira wrote: >>>> >>>>>I have a 128M computer. What are the best settings for hash and hashp when >>>>>running Crafty? >>>>> >>>>>Thank you. >>>> >>>> >>>>I would use hash=48M, hashp=16M... assuming you are using windows. If >>>>linux, hash=96m, hashp=16m will work fine... >>> >>>How about Crafty in the Fritz 5.32 interface. Any recommendations for hash >>>table size (and would this vary with the speed of the machine)? >> >> >>No idea... generally bigger is better, until you reach the point where bigger -> >>paging... then it kills you... with crafty, the disk should be quiet during >>the game (except for endgames if you have tablebases). If the disk is active, >>hash is too large and your system is paging. > >Since you indicate bigger is better except for paging I'm curious why some other >programs seem to slow down when using too much RAM for hashing. Do you have a >guess about that? >Jim Walker Sure... they are looking at the _wrong_ thing. IE "define slower". If you mean NPS drops off a bit, that is normal, because hashing improves move ordering and as move ordering gets better, nps drops. But in running a little bit 'slower' (NPS-wise) you run a good bit "better" because the hash table is improving move ordering which makes the overall search either (a) a bit faster or (b) a bit more accurate. Larger does _not_ hurt crafty until you reach the point where you start to page. Then it is a killer because disks are at least 6-7 orders of magnitude slower than memory. Urban legend is one thing, reality is another. I often run on ICC with hash= 384M, even though I play lots of bullet/blitz. I wouldn't do this if I thought it hurt performance... I don't always use this so that I can do other things on the machine without causing paging...
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