AMBER Archive (2008)

Subject: Re: AMBER: AMD Opteron: compiler recommendations?

From: Robert Duke (rduke_at_email.unc.edu)
Date: Fri Apr 25 2008 - 17:04:58 CDT

The pathscale compilers are pretty good for opterons; the pgi compilers are used for cray machines running opterons, so they must not be too bad on performance either, though there has been grief with pgi from time to time (in fairness, they have tried to fix their problems, so I should give them credit for responding to the past problems). With intel, it may be a specific switches problem; I last tried running them on opterons a couple of years ago. I preferred pathscale for the opteron, but there was not a 30% performance differential at that point in time (things could have changed). It is completely possible that my default ifort settings for the opteron are no longer the best choice (sorry, I just didn't get around to trying this combination in the current release cycle).
Regards - Bob Duke
  ----- Original Message -----
  From: Sasha Buzko
  To: amber_at_scripps.edu
  Sent: Friday, April 25, 2008 5:54 PM
  Subject: AMBER: AMD Opteron: compiler recommendations?

  Hi all,
  I've compiled sander.MPI and pmemd using Intel compilers and tested them with no apparent errors on AMD processors. However, the executables seem to be considerably faster on Intel chips (while the hardware is a bit better in that case, it shouldn't account for a 30% performance increase).

  Has anyone had any experience with comparing performance of binaries built using different compilers on AMD hardware? For instance, how do Pathscale compilers compare to Intel on Opterons? I've read reports about the evil Intel intentionally under-optimizing code on non-Intel chips, but hope it's not the issue here :).

  Any recommendations and/or benchmark results would be very much appreciated.

  Thanks in advance

  Sasha

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