Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Could someone please anaylse this to 24 ply? [diagram]

Author: Sune Fischer

Date: 00:41:39 10/04/03

Go up one level in this thread


On October 03, 2003 at 22:14:53, Robert Hyatt wrote:

>>Your last statement is inconsistent with your "If efficiency continues to climb,
>>it is unbounded."
>>
>
>It isn't if you remain "in context".
>
>You picked an equation with a simple limit.

I think Vincent only said the efficiency would rise, this doesn't imply it's
unbounded. I too got the impression that this was what he meant though.

>Vincent's "equation" has no known limit yet, because the obvious limit
>for N processors is <= N, but he has (for years) claimed efficiency > N
>for N processors.  Since N is the controlling term in any equation based
>on N, and since N is not a limit, the speedup (to me) appears to be
>unbounded, plain and simple.  Any speedup whatsoever that is >N means it
>must be unbounded.
>And we already have the >N claim in writing, many times.
>
>(not from me or anybody that knows what they are doing, however).

Anyone who understands the basics of alpha-beta knows it's absurd.
The funny thing is it can happen in practise, unfortunately it's nothing to be
happy about, it just means that your serial search isn't "optimal".
I guess a program using reversed move ordering would be quite capable of
consitently producing >2 speedups? :)

However Vincent did have an interesting point, that with N threads he can do N
probes to the hash table 'in parallel'.
Seems this would lower the latency relative to running just one thread on twice
as fast a processor where the latency (counting clocks) would just go up.
That factor has got to be peanuts relative to the parallel overhead though.

-S.



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.