[Beowulf] opteron 248 vs dual-core opteron 275

[Marc Noguera]

Hell to everyone,
I am new to this list, but I guess that this is the place to ask about 
single and dual-core opterons. I have seen many posts about this in the 
archives but while I ded get a clear idea  of dual-core being better for 
multi-threaded aplications. I still have some doubts about 
single-threades applications. We are planning to buy 10 dual CPU 
single-core opteron 248 nodes or 5 dual-CPU dual-core opteron 275 nodes, 
which is 150 Euros per core cheaper. Barebones are coming from tyan in 
both cases.
My doubts arise about the performance of 4 single-threades applications, 
on a one per-core basis. Will this performance be better on a 
2proc./4cores node or on two 2proc/2node configuration. I am talking 
about totally independent processes. I believe that the two 2proc/2node 
configuration will perform better, doen any body know if it is like this 
and if it is which relationship exists for these performances?.
On the other hand, it seems clear to me that heat dissipation of the 
dual-core configuration will be much better. Can anyone confirm that. 
Does the dual-core cpu dissipate approx. the same heat as a single-core one?
Are there many problems on the use of dual-core application by linux OS, 
or is it really a no-problemo thing as I have read?
BTW, we use our cluster mostly for computational chemistry calculations, 
mainly gaussian, turbomole, molcas and such.
Thanks for your answers
Marc
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Marc Noguera Julian
Tecnic suport a la Recerca
Despatx c7-149
Quimica Física - Universitat Autonoma Barcelona
08193, Cerdanyola del Vallès.
Barcelona, Catalunya.
Tef: 34 93 5812173
Fax: 34 93 5822920
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