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Subject: Re: 2 Chess Programs on one Computer.

Author: Dan Newman

Date: 00:33:15 04/25/98

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On April 25, 1998 at 02:06:29, Christophe Theron wrote:

>On April 25, 1998 at 00:06:01, Robert Hyatt wrote:
>
<snip>
>>
>>this isn't always safe... ie it is possible that a program computes like
>>mad when it is its turn, and then spins like mad waiting on console I/O
>>when it is not its turn...  there are some of those around and they are
>>problems for "well behaved" windows programs...
>
>Seems that Genius5 for Windows steals a lot of CPU time even when not
>thinking. Fortunately, Genius5 for DOS is provided on the same CD. You
>can prevent the DOS version from stealing resources by changing the
>program's properties under W95.
>
<snip>

This is certainly the case with CM5000 (which I believe I've
seen discussed before--either here or on rgcc).  I have a
utility called wintop (gotten from a Microsoft site as part
of a package called something like "kernel tools") which
displays all the running processes along with cpu %, time
used, etc.  (It looks alot like the VAX's topcpu program or
Unix's ps.)  As soon as you fire up CM5000 it goes to 98%
cpu usage and stays there.  It goes to about 50% when I fire
up my chess program and start it thinking.  Also wintop
shows the number of threads for each process--CM5000 has
only one.  This likely means that its Windows message loop
is set up (permanently) as a peek-message loop.  (Peek
message loops were used pre-Win-NT/95 to allow user
interaction to continue during lengthy calculations.  The
idea is that instead of waiting for a new message for the
program, you poll for messages between doing small chunks
of the lengthy calculation.  This of course is *not* the
way to do this in Win95 or NT.)

There doesn't seem to be any way to turn this behavior of
CM5000 off.  This makes any contest involving CM5000 and
carried out on one machine potentially unfair since CM5000
consumes cpu cycles on its opponent's time even if it isn't
pondering.  (You could run the contest with pondering on and
check to see (using wintop) if each process is getting
aproximately 50 percent...)

-Dan.



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