Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: "3.1 comes from running a large number of positions several years ba

Author: Robert Hyatt

Date: 09:45:43 05/06/04

Go up one level in this thread


On May 06, 2004 at 12:19:13, Gian-Carlo Pascutto wrote:

>I hope you don't mean the ones blow.
>
>Are you still claiming you 'measured' 3.1 which supposedly contradicts
>the 2.8 I measured?

I don't know what any of that refers to.  My formula came from running the BK
test (23 positions, excluding #1 an instant mate in 3).

I am trying to get the disk set up and installed now that I sent to AMD for the
last CCT event.  While I had access, I ran the BK test to get the data.  I had
promised Martin that I would post the numbers.

But you _really_ need a better vocabulary.  I have not tried to "contradict
2.8".  I have _clearly_ said that the speedup varies and that 3.1 is the value
suggested by a linear approximation fit to a non-linear function.

I do _not_ understand the obsession with "is it 2.8 or 3.1"?  It could well be
_both_.

I have _always_ called this an approximation.  Let me get the log files and grep
the times for Martin.  I'll put the logs on my ftp machine since they will be
fairly long, if you want to see the opteron data for 1-4.

>
>>Return-Path: <gcp@sjeng.org>
>>X-XS4ALL-To: <diep@maildrop.xs4all.nl>
>>Date: Fri, 9 Aug 2002 09:14:59 +0200 (MEST)
>>From: Gian-Carlo Pascutto <gcp@sjeng.org>
>>X-Sender:  <giancarlo@garf.natrese.be>
>>To: "Robert M. Hyatt" <hyatt@cis.uab.edu>
>>Cc: <diep@xs4all.nl>
>>Subject: Re: Parallel results so far
>>
>>
>>
>>On Thu, 8 Aug 2002, Robert M. Hyatt wrote:
>>
>>> Here is the results:
>>>
>>> -----------------------------------------------
>>>            ---null=2/3---        ---null=off---
>>> position   1cpu  4cpu S/U        1cpu  4cpu S/U
>>> kopec 21   27.9  10.7 2.6        30.3  12.4 2.4
>>> kopec 22   22.5   6.1 3.8        26.0   7.5 3.5
>>> kopec 23   33.5  11.2 3.0        20.9   6.4 3.3
>>> kopec 24   18.1   6.0 3.0        26.2   8.3 3.1
>>>
>>> -----------------------------------------------
>>> note.  all positions were searched for 30-45 seconds
>>> with the last 1-cpu output used to measure how long
>>> the 4-cpu search took to reach the same output (say
>>> the end of a search, or a PV move and score displayed).
>>>
>>> Vincent claimed "I never ran this test."  Thought I would
>>> run it _again_ just to expose "baloney".
>>>
>>> I think the conclusion from the above is
>>
>>Conlusions from the above? Howso?
>>
>>                speedup
>>Nullmove          3.1      +- 0.25
>>Non-nullmove      3.1      +- 0.25
>>
>>The standard errors (1SD) are way too huge to allow what
>>you try to conclude. I measured a speedup of 2.85 with
>>nullmove and 3.1 without, whereas your test wouldn't even
>>be able to differentiate between the two.
>>
>>If you want to scientifically settle this,
>>you'll need more and better data.
>>
>>(I couldn't find the CCC article reffered to earlier)
>>
>>--
>>GCP



This page took 0.01 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.