Author: Robert Hyatt
Date: 15:00:01 05/30/00
Go up one level in this thread
On May 30, 2000 at 14:54:28, Tom Kerrigan wrote: >On May 30, 2000 at 14:36:24, Gian-Carlo Pascutto wrote: > >>On May 30, 2000 at 12:50:33, Tom Kerrigan wrote: >> >>>If you're not hashing during quiescence, how are you getting hit rates around >>>40%? That's more than my percentage of non-quiescent nodes, period... >> >>I remember seeing my hitrate DROP by adding quiescence hashing...a lot >>more stuff goes in, the tables are probed a lot more, but q-positions >>do not seem to be searched as often as normal ones are, hence less hits. >> >>-- >>GCP > >I just ran a test and over 90% of my nodes are qsearch() nodes. So it's not >possible for me to have a hash table hit rate over 10%. So a 40% hit rate is >pretty amazing. > Your q-search is out of control. We had this discussion here a few years ago with myself, Bruce and Ed doing the discussing. If your q-search is > 50% of the total nodes searched, it is probably too big... There may be other things in my code that improve hash hits too, like internal iterative deepening, and so forth. >I assume that when Bob says he expects a 25% hit rate, he means 25% of the times >that the hash table is probed, and not 25% of the nodes. Which means that more >work needs to be done to estimate the speedup from the optimization that started >this thread, i.e., the equation becomes: > >speedup = (% hit rate) * (% hash probes) * (% hash move cutoffs) * (% of time >spent doing move generation) > >Throwing in some extremely optimal numbers, the result is: > >0.5 * 0.2 * 0.5 * 0.2 = 1% > >So I think the best you can hope for is 1%. Seems like too much work for too >little, to me. > >-Tom
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.