On Fri, 18 Oct 2013 12:32:00 PM Reuti wrote: > Hi, > > Am 18.10.2013 um 05:34 schrieb Christopher Samuel: > > > > We've got a group who bought themselves a 16 core 1.5TB Westmere-EX > > system and are getting what they consider to be poor memory bandwidth > > compared to an older 8 core Nehalem-EP system. > > Can you specify the CPUs in question?
X5550 for Nehalem-EP E7-8837 for Westmere-EX > > Same CPU clock speed (2.6GHz), same memory speed (1067MHz), but about > > half the memory bandwidth (single threaded). I've run my own tests > > with the Stream benchmark and can confirm the same. > > Is the speed limited by the memory chips or the mainboard, or the population > on the mainboard (i.e. often the speed drops when all DIMM banks are used). I suspect not for mainboard, this is a IBM x3690 X5's and we've also got a quad socket SGI Altix UV10 with 1TB of RAM which shows pretty much the same bandwidth. cheers, Chris -- Christopher Samuel Senior Systems Administrator VLSCI - Victorian Life Sciences Computation Initiative Email: [email protected] Phone: +61 (0)3 903 55545 http://www.vlsci.org.au/ http://twitter.com/vlsci _______________________________________________ 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
