Am 05.11.2012 um 18:23 schrieb Douglas Eadline: > >> Am 05.11.2012 um 17:50 schrieb Douglas Eadline: >> >>> --snip-- >>> >>>>> >>>>> More interesting is the ECC discussion. >>>>> >>>>> ECC is simply a requirement IMHO, not a 'luxury thing' as some >>>>> hardware engineers see it. >>>> >>>> Depends on your computational model. Would you rather spend money on >>>> ECC >>>> or on more processors? >>>> ECC comes at a cost in speed as well. There is some non-zero time >>>> required to compute the syndrome bits and do the correction on the >>>> read. >>>> Sure, you can pipeline it, but there's some extra latency inevitably >>>> added. >>>> >>> >>> I find it interesting that many users thought GPU's could not be >>> a research tool unless they had ECC memory. I have one associate who >>> turns it off because they get 10% better performance on their >>> Amber runs. >> >> Turned if off in the BIOS or installed non-registered memory? With my >> tests I couldn't see any difference in execution time whether the >> installed ECC memory is switched off or on (or even which type of error >> correction I set up in the BIOS). Comparing registered and non-registered >> memory would be a more understandable difference in execution time. >> >> Several CPUs also slow down memory access if many DIMMs are installed, so >> it seems to be better to use larger and hence fewer memory modules - which >> might be more expensive though. > > Turned off in GPU BIOS, see bottom of page: > > http://ambermd.org/gpus/#Max_Perf
Ah, thx. You were referring to GPU memory, while I meant usual main memory. Question could be: who is verifying the ECC on a GPU card? -- Reuti _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
