[Pw_forum] pw.1.3.0 and ifc 7.1

Serguei Patchkovskii ps at ned.sims.nrc.ca
Wed Dec 3 23:32:10 CET 2003

On Wed, 3 Dec 2003, Paolo Giannozzi wrote:
> > For Athlons (both XP and MP), you must choose the p3-optimized version of
> > MKL. For Opterons, both p3 and p4 versions work fine.
> did you compile pwscf on Opterons ?

Yes - with pgf90 (which is AFAIK the only Fortran-90 compiler, which supports
64-bit mode on Opteron). Unfortunately, I find that pgf90 generates very slow
code for pwscf, even with opteron-specific optimizations. ifc binary, running
in 32-bit compatibility mode (-xW and P4 MKL) outperforms 64-bit pgf90 binary
(which has twice as many registers to play with!) by a large margin, on all
(small) test cases I tried.

This was with 5.0-2 version of pgf90 - hopefully, things improved with 5.1
(which was released couple of weeks ago). However, I did not have time to
play with it yet.


Dr. Serguei Patchkovskii

Tel: +1-(613)-990-0945
Fax: +1-(613)-947-2838
E-mail: Serguei.Patchkovskii at nrc.ca

Coordinator of Modelling Software
Theory and Computation Group
Steacie Institute for Molecular Sciences
National Research Council Canada
Room 2011, 100 Sussex Drive
Ottawa, Ontario
K1A 0R6 Canada

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