[Beowulf] x86-64 NUMA vs SMP kernel: appl. performance?

[Robert G. Brown]

On Fri, 24 Sep 2004, Greg Lindahl wrote:

> > I have possible choice between using of SMP or NUMA-enabled x86_64 
> > kernels (2.4.21 from SuSE Linux 9.0 distributive).
> 
> Mikhail,
> 
> If I wanted to make a single generalization about Opteron kernels, it
> would be "Use a 2.6 kernel!" However, we've found that picking the
> right compiler is an even larger effect.
> 
> -- greg

I'd second the bit about the 2.6 kernel.  In fact, I'd say that the 2.4
kernel is almost broken on x64.  Almost because it doesn't usually
actually not work, kinda sorta.  It just works terribly poorly.

I'm interested in kernel effects on top of using e.g. FC2 with a 2.6.x
kernel.  I see balanced CPU (which one didn't in 2.4) and good
multitasking (ditto) and a fairly major improvement in throughput (all
the CPU you lost one the off processor).  What compilers have you tried,
and what improvements do they produce?

   rgb

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu