On Tue, 13 Apr 2004 16:14:04 -0500 Kevin_Gassiot@veritasdgc.com wrote:
I just got a quad cpu - 32 GB system in, and am running STREAM to confirm bandwidth. I just got this machine loaded this afternoon, but I am seeing numbers similar to what Daniel Kidger is seeing. After turning off the node interleaving in the BIOS, I get the following numbers :
single cpu - 3170 MB/sec 4 cpus - 12790 MB/sec
I am running the 2.4.21-193-smp SuSE 9.0 professional kernel.
This test depends heavily on the scheduler in the kernel; in particular on how quickly it moves new threads to the idle CPUs. Otherwise the threads allocate memory on the wrong node and your suffer. The 9.0/SLES8 kernels should 2.4 get it more or less right (scaling factor near 4 as you see) Not all 2.6 kernels do. -Andi