[gmx-users] Performance of GTX 980 and 970

[Szilárd Páll]

The 6-core Intel CPUs have only 28 PCI-E lanes rather than 40 like the
5830K/5860X which means that with a second GPU you'll get x16/x8 and
with three GPUs x8/x8/x8.

Also note that for the current GROMACS implementation, pairing a 5820K
with two 980s will likely give a rather imbalanced hardware setup -
with three 970s even more so (at least for common types of run
setups). Depending on the exact use case, you may be able to make good
use of 2-3 GPUs even with just a 5820K (e.g. in multi runs, one per
GPU) or setups with long cut-off (or without PME), but otherwise you
may not see much benefit from a second GPU, let alone a third.

--
Szilárd


On Mon, Sep 29, 2014 at 5:01 PM, Pappu Kumar <papuu_k at yahoo.com> wrote:
> Thank you for your info. I am planning to buy a computer with the following configuration:
>
> Intel 5820K
> Corsair H100i Hydro Cooling Performance
> MSI X99 SLI Plus
> Fractal Design R4
> Seasonic X 1050W
>
> I am wondering if it would be a good idea to go for 3x GTX 970 instead of 2x GTX 980 since the cost is the same. Thank you.
> --
> 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.