Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Virtual Memory

Author: Tom Kerrigan

Date: 22:55:21 01/18/00

Go up one level in this thread


On January 18, 2000 at 23:53:45, Dann Corbit wrote:
>>Having a single hash entry will not make the program much worse.
>I am surprised to hear that.  I have seen curves drawn which show a massive rise
>in ELO for the first few megabytes, which then tapers off to what appears to be
>a logarithmic increase.

If you take out a program's hash table, it may run twice as slow, but that only
translates to ~50 rating points. So it barely makes any difference in real-world
situations.

>And if a program assumes a hash table will be helpful, and always does a lookup,
>but never finds an answer, I would think that it would be slowed down quite a
>bit (wild guess: maybe 2x).

But the program has to do a lookup anyway. If anything, it's faster, because a
1-entry hash table can fit in L1 cache. And if it's never the right entry, then
the lookup logic gets to quit immediately.

-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.