>> So you could get 4GB of RAM on a processor if you use >> single ranked DIMMs.
perhaps this is TMI, but the answer depends on which cpu rev you're using (and whether the bios optimizes the memory controller.) the AMD bios-writers doc cited earlier shows that 4 dimms (2xdouble, 2xsingle) can still be used at ddr400 on rev e. no config uses >6 CS's at DDR400, and some drop to DDR333 at <=5 CS's. > Another generation of cpu/memory controllers will take us to FBdimms which > will for the most part solve the issues here... well, FBdimms maintain a high clock, but stretch latency quite a bit as you add devices. and that's some distance off, I think - rumor has it that AMD is close to shipping DDR2 support. it'll be intresting to see what kinds of latency/bandwidth/loading they achieve there. my understanding is that one of the main appeals of DDR2 is use of lower voltage - presumably for lower dissipation by the memory controller, but also possibly for easier drive of a fully-configured system at full speed. 10.7 GBps should be a nice bump up from 6.4 (peak theoretical never to be achieved in reality ;) regards, mark hahn. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
