jholewinski

Performance Discrepancy between Win7 and Linux

Discussion created by jholewinski on Aug 18, 2011
Latest reply on Aug 22, 2011 by notzed

I'm hoping an AMD dev can shed some light on a performance discrepancy I am experiencing on an HD5870 between Windows 7 x86_64 and Red Hat Enterprise Linux 6.1 x86_64.  Both machines are up-to-date with fresh installations of Catalyst 11.8.

With the OpenCL matrix multiplication sample from the AMD APP SDK 2.5, I am getting the following results:

 

RHEL 6.1 x86_64, Catalyst 11.8:
$ ./MatrixMultiplication  -i 1 -t --eAppGflops -x 4000 -y 4000 -z 4000 -b 16 -q
GFlop/s: 361.148
$ ./MatrixMultiplication  -i 24 -t --eAppGflops -x 4000 -y 4000 -z 4000 -b 16 -q 
GFlop/s: 459.921
Win7 x86_64, Catalyst 11.8:
$ ./MatrixMultiplication  -i 1 -t --eAppGflops -x 4000 -y 4000 -z 4000 -b 16 -q
GFlop/s: 321.949
$ ./MatrixMultiplication  -i 24 -t --eAppGflops -x 4000 -y 4000 -z 4000 -b 16 -q 
GFlop/s: 547.915
A ~19% difference in device performance seems a bit high.  Are there any known performance issues with the Linux drivers (11.8)?  I just want to get some "official" feedback before I spend a lot of time trying to dig deeper into this one.


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