[gmx-users] SSE4 → AVX2

[Mark Abraham]

Hi,

I'm not quite sure what you're asking, but if you want to see what CMake
has been told, you can inspect the value in the CMake cache. The easiest
way to do that is with (say)

ccmake ..

assuming that's been installed. You can also modify it in there, which some
people find easier. Otherwise, you can use

less CMakeCache.txt

from the build directory and search for the setting of interest, or more
efficiently

grep GMX_CPU_ACCELERATION CMakeCache.txt

again from the build directory.

Mark


On Wed, Aug 27, 2014 at 12:44 PM, nicola staffolani <n.staffolani at unitus.it>
wrote:

> ​T​hanx Mark!​ Is there a line command whereby I can terminal-print the
> value of GMX_SIMD/GMX_CPU_ACCELERATION once inside the right folder, which
> should be "gromacs-4.6.5"?
>
>
> 2014-08-27 12:32 GMT+02:00 nicola staffolani <n.staffolani at unitus.it>:
>
> > Thanx Szilárd!
> >
> > The concept of cross compilation is not perfectly 100% clear to me :s
> >
> > software: GROMACS 4.6.5
> > hardware: Intel® Core™ i7-4790 CPU @ 3.60GHz × 8
> > message: Compiled acceleration: SSE4.1 (Gromacs could use AVX_256 on this
> > machine, which is better)
> >
> > Have I given you the info you had requested?
> >
> >
> >
> >
> >
> > 2014-08-27 12:00 GMT+02:00 Szilárd Páll <pall.szilard at gmail.com>:
> >
> > Normally the highest supported SIMD instructions set, which is in your
> >> case AVX2, is detected during configuration phase. The fact that you
> >> are getting that message means that:
> >> - you are cross-compiling on an SSE4.1 node (e.g. cluster head node)
> >> for AVX2 machines;
> >> - your compiler does not support AVX/AVX2 and SSE4.1 was chosen as
> >> fallback; cmake should have warned about this during configuration.
> >>
> >> What is your hardware/software setup? Using -DGMX_SIMD=AVX2 should
> >> work in the former case.
> >>
> >> Cheers,
> >>
> >> --
> >> Szilárd
> >>
> >>
> >> On Wed, Aug 27, 2014 at 10:44 AM, nicola staffolani
> >> <n.staffolani at unitus.it> wrote:
> >> > Dear Gromacs users & developers,
> >> >
> >> > my computer tells me that, if I'd use AVX_256 instead of SSE4, then my
> >> > simulations would be done much faster. Which changes in which files
> do I
> >> > have to do in order to achieve this? I have serched the mailing list
> but
> >> > couldn't find the explicit answer: I warn you that I am not so much
> of a
> >> > geek, therefore suggesting me, for example, to change the path,
> without
> >> > telling me which precise actions I have to carry on (for example, as
> >> > already said, which lines I have to change/add in which file) in order
> >> to
> >> > achieve this, will only generate the next email from my side and then,
> >> > since by then you will have already started answering me, you will
> lose
> >> > more time answering me back than if you would have precisely described
> >> in
> >> > the first reply the order of precise actions needed to be done in
> order
> >> to
> >> > achieve the goal ;)
> >> >
> >> > Thank you for helping and have a nice day/night,
> >> >
> >> > Nicola
> >> > --
> >> > Nicola Staffolani PhD
> >> > Biophysics & Nanoscience Centre CNISM <
> http://www.unitus.it/biophysics>
> >> > Università della Tuscia
> >> > Largo dell'Università s.n.c., I-01100 Viterbo
> >> > email: n.staffolani at unitus.it
> >> > tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36
> >> > --
> >> > Gromacs Users mailing list
> >> >
> >> > * Please search the archive at
> >> http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before
> >> posting!
> >> >
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> >> >
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> >> --
> >> Gromacs Users mailing list
> >>
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> >
> >
> >
> > --
> > Nicola Staffolani PhD
> > Biophysics & Nanoscience Centre CNISM <http://www.unitus.it/biophysics>
> > Università della Tuscia
> > Largo dell'Università s.n.c., I-01100 Viterbo
> > email: n.staffolani at unitus.it
> > tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36
> >
>
>
>
> --
> Nicola Staffolani PhD
> Biophysics & Nanoscience Centre CNISM <http://www.unitus.it/biophysics>
> Università della Tuscia
> Largo dell'Università s.n.c., I-01100 Viterbo
> email: n.staffolani at unitus.it
> tel.: +39 0761 35 70 27; fax: +39 0761 35 71 36
> --
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>
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