Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Hashing and draw by repetition

Author: Robert Hyatt

Date: 20:07:20 08/27/99

Go up one level in this thread


On August 27, 1999 at 17:51:53, KarinsDad wrote:

>On August 27, 1999 at 16:09:21, Robert Hyatt wrote:
>
>[snip]
>>
>>
>>Not to mention the fact that you have to have a hash table big enough so that
>>entries don't get overwritten?  My xeon has 512mb, but that isn't _near_ enough
>>to guarantee that I can keep everything...
>>
>>Sounds like overkill that will really slow you down, for minimal gain...  but
>>it is worth experimenting with...
>
>
>I agree. But, I'm trying it none the less. My experiments have shown that the
>parent links are really helpful. The child links, much less so.
>
>But, even if I get 100,000 nodes per second, 240 seconds for a 4 minute search,
>and 128 bytes per "extended sized node", I would have to have a hash table size
>of about 3 GB if I wanted to save every node. So, with about a 100 MB hash
>table, I can only hang onto about 3% of the nodes. So, I have to find a way to
>remove 97% of the nodes. Even if I could drop this down to 80 bytes or so, I
>would still have to get rid of 95% of the nodes, so the space issue does not
>seem to be a major factor here. I do have a lot of stuff in my hash nodes which
>I could probably do in another way, but for now, the extra 40 bytes or so due to
>the links per node do not seem to be the critical factor (yet). And, even if I
>drop the child nodes completely (these are easy to remove, the parent nodes
>though are critical to my current search/hash design), this would only save
>about 20 bytes or so on average.
>
>KarinsDad :)


if your math is right, doesn't that mean that 95% or more of your tree is not
'linked'???  ie how does the parent/child pointers work if you can only store
3% of the tree in the first place???



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.