[pymvpa] pprocess and number of CPU cores?

[Matthias Ekman]

Dear Experts,

we are currently planning to buy a new server mainly for pymvpa-stuff. I 
would like to ask you if you have any experience how well the new 
pprocess implementation of the searchlight algorithm scales with the 
number of CPU cores (beyond 8 cores).

In this commit Michael points out 25% speed-up for 2 cores (and 250% for 
8 cores):
http://github.com/hanke/PyMVPA/commit/cb9a01183cb8103ee9377cc4f66598124dbd7af3

But later on some improvements were made leading to a speed-up of 65% 
for 2 cores:
http://github.com/hanke/PyMVPA/commit/7819dc8214bdd63f10185c1381bb3165edf49036

I am thinking about 2x 8 cores (lower clock speed) vs. 1x 12 cores 
(higher clock speed) which would be the same price range. With good 
scaling I would prefer the 2x 8 cores.

Btw: thanks for the pprocess implementation! Its a great feature.

Thanks in advance,
  Matthias