[Pw_forum] Re: Woodcrest vs Opteron performance in pwscf calc.

[Konstantin Kudin]

> You mentioned NUMA enabling on opteron machines, I wonder if it's a
> default
> function of kernel 2.6.9-xx. If it's not, I need to turn it on in 
> re-configuration of
> the kernel and recompile, right?

 I think there could be BIOS settings that affect this (motherboard
specific), and also the kernel needs to be set properly too. Your
version looks fresh enough to have it. 

 We have here duals with NUMA on, and quads with NUMA off. So 2 duals
at 2.0Ghz over 1Gbit beat the quad at 2.2Ghz by like 20-30% (the quad
needs NUMA off due to problems with another package).

 Also, consider using the GOTO blas. When I checked, for CP it gave
almost miraculous speed-ups over stuff like ACML, which appears to be
nothing more than a bunch of standard fortran routines compiled with
some optimizations :-) Even Atlas BLAS might be more advanced than that
... Just link whatever BLAS you have first, and then something else to
have LAPACK. Something like this:

../flib/ptools.a ../flib/flib.a ../clib/clib.a ../iotk/src/libiotk.a 
/home/kostya/lib/libgoto64.so -lpthread
/home/kostya/lib/acml/gnu64/lib/libacml.so -lg2c
-L/home/kostya/lib/fftw-2.1.5v/fftw/.libs -lfftw

 Kostya
 

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