[parsec-users] Question about # of threads for ferret-parallel
msinclair at wisc.edu
Wed Feb 9 17:02:27 EST 2011
2011/2/9 kishore kumar <kishoreguptaos at gmail.com>:
> Hi Matt,
> As far as I have seen, the *good range* (that gives max performance)
> depends on the number of cores on your machine. Actually ferret is a
> scalable application, I mean that it gives max performance when the
> total number of threads created is more than the number of cores of
> the machine (performance increases along with increasing thread counts).
> According to the implementation, it creates (n * 4) + 3 threads with the
> command line option value of n. On my 24-core AMD Opteron Solaris
> machine, it gives best performance with a total of 63 threads
> (corresponding command-line parameter value n is 15).
> On 9 February 2011 13:46, Matt Sinclair <msinclair at wisc.edu> wrote:
>> Hi everyone,
>> I have a question on the default run parameters for ferret. I can see
>> from the ferret-parallel.c program that several of the stages take
>> their number of threads from the input parameters (parameter #6 to be
>> specific). However, in running the default tests:
>> parsecmgmt -a run -p ferret -c gcc-pthreads -i [test, native]
>> I see that parameter #6 is always set to 1 (for test and native at
>> least), which implies to me that the number of threads in the default
>> tests is always 1. I realize that you can change this on the command
>> line with the -n option, but I was wondering if this was intentional?
>> If so, is it written somewhere what a good "range" of threads for
>> ferret is? Thanks again for the help!
>> Matt Sinclair
>> University of Wisconsin-Madison
>> College of Engineering, ECE Dept.
>> Vertical Research Group
>> parsec-users mailing list
>> parsec-users at lists.cs.princeton.edu
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