HI Ross:
thank you very much for your such detailed reply.
I've got two GTX590 in a workstation and all jobs are running
locally. I compared the same system with series and MPI running:
single series running can up to 27.4 ns/day, but it is unstable and it
can change to 13 or even 10 ns/day from time to time....
the MPI running I use mpirun -np 2 +..... for running, and it is around
18 ns/day.
I am not sure whether series running jobs on GTX590 can distribute to
both logical cores. I only submit one job when I did each test.
at present, it only works under GCC compiled Amber12 and it doesn't work
for intel compiled version. However the CPU version works fine for both
GCC and ifor/icc version.
thank you very much
best
Albert
On 05/08/2012 06:50 PM, Ross Walker wrote:
> Hi Albert,
>
> The GTX590s are pretty terrible cards - at least for running jobs in
> parallel so I really wouldn't bother. Only run serial jobs on them, two
> total, one on each of the GPUs reported by devicequery.
>
> If you are seeing variation in performance for serial GPU runs then it is
> likely that other stuff is running on your machine that is interfering. Are
> other users on the machine? Do you have other jobs running? Does the machine
> run X windows? - If you are running multiple jobs on the same physical GPU
> (not card but GPU - a GTX590 card has 2 GPUs) then you will likely see
> massive performance degredation.
>
> You might also have issues if you are writing to a remote file system (over
> NFS for example) but this is normally not so large a variation. The factors
> of '2' in the numbers you quote (27 ca= 28, 14, 7) suggests to me that you
> are running more than one process on a single GPU.
>
> Unfortunately without more specific details of how your machine is setup,
> what is running, some output from top etc it is difficult to offer more
> suggestions.
>
> All the best
> Ross
>
>> -----Original Message-----
>> From: Albert [mailto:mailmd2011.gmail.com]
>> Sent: Tuesday, May 08, 2012 1:36 AM
>> To: AMBER Mailing List
>> Subject: [AMBER] strange CUDA benchmark
>>
>> Dear:
>>
>> I am testing a CUDA benchemark based on Amber 12+GNU, I use the same
>> system under GTX590 for testing. Some times I can get as high as 27
>> ns/day, sometimes it 14 ns/day, sometimes it is even only 7 ns/day.....
>>
>> I do the test in the same directory and don't modify any parameters. I
>> am just wondering what happen?
>>
>> thank you very much
>> Albert
>>
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Received on Tue May 08 2012 - 10:30:03 PDT
