Author: Vincent Diepeveen
Date: 15:32:21 08/21/02
Go up one level in this thread
On August 21, 2002 at 17:55:44, Robert Hyatt wrote:
>On August 21, 2002 at 17:32:11, Gian-Carlo Pascutto wrote:
>
>>On August 21, 2002 at 17:25:23, Robert Hyatt wrote:
>>
>>>And it is just as accurate
>>>as trying to count nodes.
>>
>>It isn't, because the NPS changes, which is just what I said.
>>
>>--
>>GCP
>
>
>It doesn't change _that_ much on the last 3-4-5-6 searches. At least it
>doesn't for me in the results from Cray Blitz on 16 and 32 cpus... Once
Let's jump onto this nodes a second.
Let me quote some text written by you.
DTS article 1997, march 1997. Issue 1 advances in computerchess.
Not exactly a CCC a bit way more official.
page 16 table 3 and 4:
16 processors 155,514,410 nodes needed: 311 seconds = 500046 nodes
a second
8 processors 109,467,495 nodes needed: 274 seconds = 399516.4 nodes
a second.
So despite 8 processors more, you didn't get twice as much as nodes
a second more. In fact you lost 60% speed there in nodes a second.
This was all tested at the same machine you write in the same article.
They were busy idling at the 16 processor?
BTW, where are your 32 processor results? I have never seen them in any
publication. yet your test is pretty simple. Just a 24 positions and
you only need to get near the same depth of the 16 processor search.
Should be theoretical under an hour...
Best regards,
Vincent
>those two programs get to the 1-2 second mark, the cpus stay busy, period.
>Just like Crafty. I don't believe DB had any such problem either, once
>you get beyond the first search result they outputted for a iteration...
>
>You could test your hypothesis however, by seeing if the first couple
>of branching factors are worse than the last couple for each search...
>If they are similar, this isn't a problem...
>
>I might try this tonight late, for one log file...
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