I was checking the performance of numademo stream test on a system I have stumbled upon (Iwill H8501 8way 8-GB in 16 512MB dimms). The results were pretty low (around 1600MB/s on all tests), so I proceeded to check weather node interleaving was disabled in the BIOS. Everything was set up with factory defaults (node interleave OFF, bank interleaving ON). Checking the kernel log (SuSE w kernel 2.6.13-15.8-smp x86_64), I found this: SRAT: Node 0 PXM 0 0-ffffffffffffffff SRAT: Node 1 PXM 1 0-ffffffffffffffff SRAT: Node 2 PXM 2 0-ffffffffffffffff SRAT: Node 3 PXM 3 0-ffffffffffffffff SRAT: Node 4 PXM 4 0-ffffffffffffffff SRAT: Node 5 PXM 5 0-ffffffffffffffff SRAT: Node 6 PXM 6 0-ffffffffffffffff SRAT: Node 7 PXM 7 0-ffffffffffffffff SRAT: pxm 0 overlap 0-9fc00 with node 1(0-ffffffffffffffff) SRAT: SRAT not used. I'm no expert, but I guess that means it assigns all memory, from byte 0 till 2^64 to each node. Not surprisingly acpi_numa_memory_affinity_init in srat.c finds it to overlap and proceeds to ignore the information. The question is: is this the problem (we also experience random crashes when running a 2GB+ simulation) causing low memory performance? How can I solve it? I can provide logs and do tests as requested. Thanks!