[gmx-users] Performance difference when using Gromacs 5.0 with different vector instructions
mingtha at scarletmail.rutgers.edu
Fri Oct 20 00:18:15 CEST 2017
Thanks for the quick response. So, in general, running using AVX
instructions will yield
better performance than SSE4.1?
On Thu, Oct 19, 2017 at 5:18 PM, Mark Abraham <mark.j.abraham at gmail.com>
> In short, yes. See
> You should generally always use a GROMACS binary compiled for the highest
> SIMD level supported by your hardware. Your mdrun .log file will advise you
> when it observes that you are not.
> On Thu, Oct 19, 2017 at 7:02 PM MING HA <mingtha at scarletmail.rutgers.edu>
> > Hi all,
> > I am running several resources using Gromacs 5.0 to run my simulations.
> > On some resources, Gromacs is compiled using SSE4.1 SIMD instructions,
> > while on others AVX_256 or AVX2_256 is used. While I don't find much of a
> > performance difference between AVX_256 and AVX2_256 instructions, there
> > is a large performance difference between resources that use SSE4.1 and
> > AVX instructions. Specifically, resources using SSE4.1 are about 2-3x
> > slower
> > than those that use AVX.
> > I'm kind of new to the SIMD instructions used by Gromacs, so I was
> > wondering
> > whether the instruction set is causing the large performance difference.
> > Sincerely,
> > Ming
> > --
> > 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.
> 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.
More information about the gromacs.org_gmx-users