[petsc-users] same code, different machine, different performance

[Matthew Knepley]

On Wed, Jul 30, 2014 at 2:10 AM, 张国熙 <altriaex86 at gmail.com> wrote:

> I am using putty so I could only give you screenshots.
> The attachments are full output.
>

As we can see below, the memory bus on this machine can only really drive
1.5 processors. For that algorithm, you will see some speedup on 2 procs,
and nothing after that. It would be nice if manufacturers reported STREAMS
along with their CPU benchmarks.

  Thanks,

     Matt


> The output
> [image: 内嵌图片 1]
>
>
> 2014-07-30 16:44 GMT+10:00 Jed Brown <jed at jedbrown.org>:
>
>> 张国熙 <altriaex86 at gmail.com> writes:
>>
>> > Do you mean compling and running the file "noname" attached?
>> > Is it a source code? After opened it I only see the following.
>> >
>> > *-----BEGIN PGP SIGNATURE-----*
>>
>> It isn't called "noname", it is a PGP/MIME signature
>> (application/pgp-signature) and your mail client refuses to recognize a
>> 15-year old standard and instead writes "noname".  Just ignore my
>> signatures and do what I suggested, then reply-all (do not drop
>> petsc-users).
>>
>> > *Version: GnuPG v2*
>> >
>> > *iQIcBAEBAgAGBQJT2JCbAAoJEM+2iNHeMalNOhQQAJ9xVEBPCJhEB3PkVhCwNg/e*
>> > *djetm4dAcWoRtv262lGU+yoe1W88WVNQBrHyJCXn7SBZ7sYvUM7lUgDxbBhWIILj*
>> > *CwasnKDj2/r/TjmNmxwaP/xtKAJya6lfzKCQr6wymOQRCikGGCKZxNz+XfD5HI7j*
>> > *wF9kjfUI/oDTm7beBi21z+GXaDHx0uq9rIIrn2kG2Bkv2OFYbAa/YKi6SuPxF7aa*
>> > *kxbEchusp9WPChBqlmB6e+E991YwvUPQuaeXdN9do1YLuk9SPZYVmVbj7fdBrkB6*
>> > *tfgoJIQW80mOCJFu13HqA22MzaQikaztW4B8zRguL1YIDhKmu+moi8gvlbkH+HjZ*
>> > *L+PuIIKaozlkiHSy7KzhHpP8m6JuJqNoI7nkMwd2Ye4AF9xUFBiuzf426xafroF0*
>> > *cLXLR1AMFXpRy4fRwZpiFdiyu4ats6jPOQ2WsJhS147WldShG+dMgo6acWaWq30v*
>> > *RPqyWJV478cjZ8ZFsf6hdHoiMjfqPDxi4XF+b0+OeY+gM8CG+1h9HYpo6E+ALo1Q*
>> > *IVKLI5cLfvshACrCPY1vnehDYSJMCPD91X+zlfjm/wrWb4Ci+RH+WGovIW0Smb72*
>> > *NaGu1EDqZnUIFbjQA8wX1/E31uwVmr18Z2OJnqaWaas4Fnc53aro02Lya2Xn7/yf*
>> > */kBlARwztc6/U6oUHFf+*
>> > *=qGvR*
>> > *-----END PGP SIGNATURE-----*
>> >
>> >
>> > 2014-07-30 16:28 GMT+10:00 Jed Brown <jed at jedbrown.org>:
>>
>> >
>> >> 张国熙 <altriaex86 at gmail.com> writes:
>> >>
>> >> > Hi,all
>> >> >
>> >> > Recently I am using SLEPc to solve an sparse eigenvalue problem. I
>> use
>> >> > krylov-shur and mumps as solvers.
>> >> >
>> >> > My codes work well my corei5 dual core laptop. Compared to my old
>> >> > sequential solution ARPACK/UMFPACK, running with 2 process could
>> give me
>> >> > 1.3x speedup. However when I install my code on another station with
>> quad
>> >> > core CPU, the performance change significantly. My parallel code
>> runs 2-3
>> >> > times slower than sequential code.
>> >>
>> >> Run "make streams NPMAX=4" and send the output.
>> >>
>>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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