Dear Rafael, It really depends on the processors, GPUs, as well as whether you are interested in performance or performance/buck. Also note, that with GPUs you'll need considerably more atoms/core.
First of all, the E7-s are 8-core processors, so four of them is only 32 (and from what I can see it doesn't have HT). Moreover, they cost a whopping ~2500 USD each. In contrast a pair of Westmares go for the about price of one E7 (some less) and then you can get Teslas (although these cost quite a lot) or even GF GTX580-s -- which by the way are ~30-40% faster and 4-5x cheaper. With two GPUs you will probably not match the 4xE7 performance -- maybe with GTX580s --, but with 3-4 you probably will. However, you might want to look at AMD-based servers as well, they have *really* good performance/price ratio, so when it comes to ns/day/$ dual-/quad-socket AMD machines can get close to Westmere+GPU combination, but not quad-socket Intels can't. One last tip: unless you really need so compute power in one single machine, you can also consider the budget option of getting desktop Sandy bridge with say two budget-ish GF cards (e.g. 570/560 Ti) and you'll have an entire box with everything below 1000 USD. Regards, -- Szilárd PS: I hope you don't mind the USD prices, it was easier to google those than EUR ones. On Tue, Nov 29, 2011 at 10:14 PM, <raf...@us.es> wrote: > Dear Szilárd, > now 64 cores machines are available, for instance, using Xeons E7-8837. Do > you have any idea about which combination will give more performance? I > mean, 64 CPU cores or 16-32 CPU cores + 4 C2075 or similar. The limit of 4 > GPUs is imposed by the MB of the machine I have in mind. > > Thanks for the information. > > Sincerely, > Dr. Rafael R. Pappalardo > Dept. Quimica Fisica, Univ. de Sevilla (Spain) > > On Tue, 29 Nov 2011 22:04:08 +0100, Szilárd Páll wrote: >> >> Hi Andrzej, >> >>> One more question: will a ratio of gpu/cpu units and cores be of >>> importance >>> in next gromacs releases ? at the moment the code uses one core per gpu >>> unit, wright ? When the code is gpu parallel how can this change ? >> >> Yes, it will. We use both CPU & GPU and load balance between them. For >> optimal performance you'll want up to 4-8 cores/GPU, but ultimately it >> depends on the performance of each. >> >> -- >> Szilárd >> >> >>> Thank you >>> >>> Andrzej >>> -- >>> gmx-users mailing list gmx-users@gromacs.org >>> http://lists.gromacs.org/mailman/listinfo/gmx-users >>> Please search the archive at >>> http://www.gromacs.org/Support/Mailing_Lists/Search before posting! >>> Please don't post (un)subscribe requests to the list. Use thewww >>> interface >>> or send it to gmx-users-requ...@gromacs.org. >>> Can't post? Read http://www.gromacs.org/Support/Mailing_Lists >>> > > -- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > Please don't post (un)subscribe requests to the list. Use the www interface > or send it to gmx-users-requ...@gromacs.org. > Can't post? Read http://www.gromacs.org/Support/Mailing_Lists > -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
