[Beowulf] [gorelsky at stanford.edu: CCL:dual-core Opteron 275performance]

Mikhail Kuzminsky kus at free.net
Wed Jul 6 10:59:33 PDT 2005

In message from Jakob Oestergaard <jakob at unthought.net> (Wed, 6 Jul 
2005 16:43:00 +0200):
>On Wed, Jul 06, 2005 at 04:12:25PM +0200, Alan Louis Scheinine wrote:
>> My main point is, as I wrote, "your milage may vary."  I've heard 
>> various
>> people that "everybody is going to dual-core".  I simply want to 
>> that
>> the dual-core choice is not for everybody.  In particular, I looked 
>> profiling
>Guys, the results are very interesting - it would be very interesting 
>know, too, which kernels you have been running on.
>For some time there have frequently been fixes to the NUMA code in
>general, and there's definitely been some changes for handling 
>processors in the opteron case.
>If, and I don't know if this is the case, the kernels you have tested
>with do not properly understand the topology of your NUMA setup in
>dual-core (two processors (cores) per node (memory controller)),
>performance should definitely be expected to degrade noticably.
>I'm pretty sure at least 2.6.12 had NUMA/dual-core fixes in it. 
>if you're running older 2.6 kernels it would probably be interesting 
>try a more up-to-date kernel.
I'll try to test dual cores Opteron w/2.4 kernel and 2.6 kernel,
but if I'm correct, SuSE 9.3 (we plan to use) has a bit more old 2.6 
BTW, may be there some difference in tests performance between 2.4 and 
more old 2.6 kernels ?


>Thanks for the results and observations - it's a good read :)
> / jakob
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