I have noticed a bug in the new v21.1 program regarding Athlon computers.
The CPU type gets changed from Athlon to Pentium II. This happens in both
Prime95 v21.1 and NTPrime v21.1. Worse yet, it happens every time the
program/service is started. I realize that this changes the projected end
date but there may be other consequences that I am not aware of.
Dan
-----Original Message-----
From: George Woltman [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, June 20, 2001 3:55 PM
To: [EMAIL PROTECTED]
Subject: Mersenne: More v21
Hi all,
Regarding some of the comments on v21:
The strange data output when doing an Advanced/Time on 10,000,000
is due to some instrumentation I accidentally left in. I have removed it
and
maybe it will speed up the program by a very, very, very tiny amount.
You can download it at ftp://mersenne.org/gimps/p95v21a.zip
I've built a Windows NT Service version and a Linux version. You
can
download them at ftp://mersenne.org/gimps/p95v21n.zip and
ftp://mersenne.org/gimps/p95v21x.zip respectively. They have been
through the "robust" QA process of proving M11213 prime. Use
at your own risk! Brian Beesley, a big QA volunteer, will undoubtedly
download the Linux version and report bugs or a higher level of confidence
in mprime's capabilities.
Since the prefetch code seems to work on the Athlon, I won't be
needing the services of Athlon programmers or Orlando residents just now.
Thanks to those that offered. Although, I'm sure we could get a few more
percent by using PREFETCHW or by a modified memory layout for the
64-byte cache lines, I'll wait until v21 is finalized before looking at any
more changes.
Finally, the PPro, PII, and Celeron 1 do not crash when a prefetch
instruction is encountered. This indicates to me that Intel planned on
putting
this instruction in prior to the PIII but ran into technical difficulties
or time
constraints. These CPUs are affected only by the prefetch instructions
using up some cache space and decoder bandwidth. Thus, I'm reluctant to
increase prime95's size by a third to support 4 different FFT algorithms:
Pentium classic, Pentium Pro, Pentium Pro with prefetching, and SSE2.
I haven't made a final decision yet (although I sure wish I'd put the FFT
code
in a DLL!)
Regards,
George
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