Thank you very much Mirco and Szilard for the clarification. This helps a lot.
Regards, D. 2015-06-15 16:10 GMT+02:00 Mirco Wahab <mirco.wa...@chemie.tu-freiberg.de>: > On 11.06.2015 14:07, David McGiven wrote: > >> Your 1-3% claim is based on the webpage you linked ? >> >> Is it reliable to compare GPU performances for gromacs with those of 3D >> videogames ? >> > > OK, you got me on this. As much as I'd wish I cannot > really back up my claim of comparability. I have been > out of office for one week but did some tests here > for myself today. > > The system is Haswell/E (i7-5820K), GPU is single GTX-980 > (the "normal" Gigabyte Model), the test run is ADH-cubic-vsites > (reaction field) from the bottom of the Gromacs acceleration page > (http://www.gromacs.org/GPU_acceleration). > > I can explicitly set the PCIe-x16 slots to 1.0, 2.0, and 3.0 > (which I did). Theoretically (and practically), PCIe-x16 2.0 > should be relatively close in bandwidth to PCIe-x8 3.0, so this > should give some hints as what to expect. > > adh-cubic-vsites/rf - ns/day: > PCIE-x16/1.0 54.46 > PCIE-x16/2.0 61.81 > PCIE-x16/3.0 64.52 > > percentage related to PCIE-x16/3.0 > PCIE-x16/1.0 84.4 > PCIE-x16/2.0 95.8 > PCIE-x16/3.0 100 > > (each value = avg. of three runs) > > Therefore one could support the hypothesis > that using one card in x16 and one in x8 > would probably show a performance penalty > of around 5% on the x8 card. > > Regards > > M. > > > -- > 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.
