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 <papu...@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-requ...@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-requ...@gromacs.org.
