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Re: k8-smp

Francesco Pietra wrote:
After the installation of amd64 etch with generic kernel, I chose a kernel for multi dual opteron.
uname -a reports:
Linux debian 2.6.15-1 amd64-k8-smp # SMP

In view of compilation, I I wonder about the following:

Dual (or more) Opteron designs are not SMP (Symmetric Multi Processor), but NUMA (Non-Uniform Memory Architecture). With SMP the two CPUs share the same bus to memory, but with NUMA each CPU hassome local memory connected to a local memory bus. The other CPU can still get to that memory, but it's a bit slower. If you would only putin 1x 2GB, you will severely slow down the other CPU cause it has to go through the other CPU to do memory accesses. See ftp://ftp.tyan.com/datasheets/d_s2895_101.pdf The cpu design may have a bearing for the compilation of programs for multiprocessor systems, like mpqc (in the compilation notes, mpqc refers to "symmetric multiprocessor", see http://www.mpqc.org/mpqc-snapshot-html/compile.html.

It's called SMP for traditional reasons - don't worry, it's perfectly appropriate for NUMA systems like Itanium and Opteron

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