[Beowulf] performance tweaks and optimum memory configs for a Nehalem
hahn at mcmaster.ca
Sat Aug 8 18:47:47 EDT 2009
> Is it a bad mistake to configure a Nehalem (2 sockets quad core giving
> a total of 8 cores; E5520) with 16 GB RAM (4 DIMMs of 4GB each)? I
there's no ambiguity here: unpopulated channels decrease bandwidth
and/or concurrency. (does anyone know whether nehalem can "ungang"
memory channels like opteron can? it would be fascinating to see
benchmarks showing a benefit to higher memory concurrency for a
> Our code requirements dictate 2 GB / core is enough. Should I be
> paying for the additional RAM to make it 24 GB?
ram is, historically and relatively, cheap. otoh, can your code get
by with 1.5G/core? actually, I tend to see some association with
smallish memory footprints (2G/core is definitely not large) with
cache-friendliness. this would argue that the higher bandwidth may
not make much difference to your code...
regards, mark hahn.
Beowulf mailing list, Beowulf at beowulf.org sponsored by Penguin Computing
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
More information about the Beowulf