Take a good look at the code. You can probably get a better IPC out of it with a few cores by using a tricky form of parallellisation. Yet then it stops as far as parallellization is concerned :)
On Jan 9, 2013, at 2:05 PM, Jörg Saßmannshausen wrote: > Hi John, > > I was toying with this idea as well. However, what I do not know > is: as it is > a single core job, do I really need the second CPU for the memory > management > or would that slow down things? In other words, does it look like > that: > Memoryrequest CPU#0 -> CPU#1 -> RAM > So if I am using a single socket motherboard, would that not be > faster or does > a single CPU not cope with that amount of memory? > > Regards > > Jörg > > On Wednesday 09 January 2013 12:53:41 you wrote: >> You will need to populate all of the CPU sockets if you are filing >> all the >> DIMM slots. >> So yoy probably need more than one CPU >> On Jan 9, 2013 12:42 PM, "Jörg Saßmannshausen" >> <[email protected]> >> >> wrote: >>> Dear all, >>> >>> Happy New Year! >>> >>> I was wondering whether people on the list here have some first hand >>> experiences with this. I have been asked to purchase a single >>> machine >>> with around 500 GB of RAM. We would not need more than 8 cores >>> here. The >>> job >> >> simply >> >>> needs that much of memory (and even then it is running for 14 days). >>> >>> Now, with that amount of memory used by a single core, I would have >> >> thought >> >>> that I need a fast memory interconnect, i.e. a high memory >>> bandwidth. I >> >> was >> >>> thinking of getting an Intel Sandybridge CPU (maybe a E5-2650) >>> for that >>> machine and get a motherboard with can cope with that amount of >>> memory. >> >> Does >> >>> anybody happen to have some recommendations here or knows of >>> potential >>> pitfalls? >>> >>> Also, in a related problem, how would I set the kernel.shmmni, >> >> kernel.shmall >> >>> and kernel.shmmax values so I am not running out of memory >>> handles here. >> >> I am >> >>> still confused by that. >>> >>> Any kind of advice here is much appreciated. Given it is an >>> expensive >> >> piece of >> >>> hardware we want to purchase I want to get it right. >>> >>> All the best from a grey London >>> >>> Jörg >>> >>> -- >>> ************************************************************* >>> Jörg Saßmannshausen >>> University College London >>> Department of Chemistry >>> Gordon Street >>> London >>> WC1H 0AJ >>> >>> email: [email protected] >>> web: http://sassy.formativ.net >>> >>> Please avoid sending me Word or PowerPoint attachments. >>> See http://www.gnu.org/philosophy/no-word-attachments.html >>> >>> _______________________________________________ >>> Beowulf mailing list, [email protected] sponsored by Penguin >>> Computing >>> To change your subscription (digest mode or unsubscribe) visit >> >> http://www.beowulf.org/mailman/listinfo/beowulf > > -- > ************************************************************* > Jörg Saßmannshausen > University College London > Department of Chemistry > Gordon Street > London > WC1H 0AJ > > email: [email protected] > web: http://sassy.formativ.net > > Please avoid sending me Word or PowerPoint attachments. > See http://www.gnu.org/philosophy/no-word-attachments.html > > _______________________________________________ > Beowulf mailing list, [email protected] sponsored by Penguin > Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
