[gmx-users] FFTW with AVX

[Oliver Schillinger]

Ah great, sorry.
Google showed me the old version (for the 5.0 release) of the site!
Great work, thanks!

On 01/04/2016 03:02 PM, Mark Abraham wrote:
> Hi,
>
> No,
> http://manual.gromacs.org/documentation/5.1.1/install-guide/index.html#using-fftw
> is
> consistent - use both --enable-sse2 and --enable-avx. Earlier documentation
> was incomplete - the important thing is that even if the hardware is AVX,
> with up to and including FFTW 3.3.4, performance is best if FFTW is
> configured with both SSE and AVX support (and the latter tends to be only
> of minor importance).
>
> Mark
>
> On Mon, Jan 4, 2016 at 2:36 PM Oliver Schillinger <
> o.schillinger at fz-juelich.de> wrote:
>
>> Hi there,
>> I just noticed that when I compile gromacs 5.1.1 with
>> GMX_BUILD_OWN_FFTW=ON, it compiles fftw with avx support (at least that
>> is what cmake reports: "The GROMACS-managed build of FFTW 3 will
>> configure with the following optimizations: --enable-sse2;--enable-avx").
>> However, in the online installation instructions it is noted that avx
>> might slow down the computation and its use is discouraged.
>> Is this information outdated or are the defaults that gromacs uses for
>> the fftw compilation not optimal (and how do I change them)?
>> Cheers,
>> Oliver
>>
>> --
>> Oliver Schillinger
>> PhD student
>>
>> Computational Biochemistry
>> Institute of Complex Systems 6 - Structural Biochemistry
>> Building 5.8v, Room 3010
>> Phone:  +49 2461-61-9532
>> Mobile: +49 172 53 27 914
>>
>> Forschungszentrum Juelich GmbH
>> 52425 Juelich
>> Sitz der Gesellschaft: Juelich
>> Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498
>> Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher
>> Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender),
>> Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt,
>> Prof. Dr. Sebastian M. Schmidt
>> --
>> Gromacs Users mailing list
>>
>> * Please search the archive at
>> http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before
>> posting!
>>
>> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>>
>> * For (un)subscribe requests visit
>> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
>> send a mail to gmx-users-request at gromacs.org.
>>

-- 
Oliver Schillinger
PhD student

Computational Biochemistry
Institute of Complex Systems 6 - Structural Biochemistry
Building 5.8v, Room 3010
Phone:  +49 2461-61-9532
Mobile: +49 172 53 27 914

Forschungszentrum Juelich GmbH
52425 Juelich
Sitz der Gesellschaft: Juelich
Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498
Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher
Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender),
Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt,
Prof. Dr. Sebastian M. Schmidt