Hallo Barnet, Montag, 8. Oktober 2007, meintest Du:
BW> I'm moving towards setting up a small cluster (my first), and am BW> thinking about using Intel quad core processors. However, I'm a little BW> concerned about memory contention. I'm (tentatively) going to have one BW> processor per node (this appears to be the cheapest way to go), but I BW> still wonder whether four cores will choke Intel's memory architecture. BW> (AMD's Barcelona may be better in this regard, but it doesn't seem to be BW> available yet, at least not through retail channels). Yes intel does have a memory bandwidth problem.... BW> I'd like to hear any opinions on this issue. And if you've used quad BW> core processors, I'd certainly like to hear about your experiences BW> (including which processor you've used). ... but it does not to affect performance as hard as one could think. How big the impact is depends mostly on your application. I saw code scaling very good (HPL for example ;-) ) and others where you just get 10% more out of using 8 instead of 4 cores (on a dual socket quadcore system). Another aspect that you should think of is the i/o intensity of your application. Remember that 4 cores in a single socket system will share the same interconnect port. That could hit performance pretty bad. A high speed interconnect could be a solution to that problem but will cost you money. Conclusion: the only good benchmark is your own application. The Intel DualCore performs quite good on a wide range of applications. The QuadCore performs good on some of 'em - but as you said: it seems to be the only available (through retail channels) quadcore to the market right now... Regards Jan _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
