[R-sig-Debian] R and multi cpu ATLAS

[Andrew Piskorski]

On Thu, Jun 03, 2010 at 11:31:02AM -0500, Paul Johnson wrote:

> I wonder, though, if you can point me at some documentation that says
> how it is *supposed* to work with R and Atlas. From what I can tall, R

I don't think R is immediately relevant to the question here.  The
Atlas docs are pretty clear that Atlas will run multi-threaded, using
up to N cores, IFF it is compiled to do so.  The limit N is set at
compile time:

  http://math-atlas.sourceforge.net/faq.html#tnum

On my dual-core laptop running Ubuntu 9.04, the libatlas-test programs
also run using only one core.  So, I doubt this has anything to do
with R, most likely the Ubuntu Atlas packages are built to use one
thread only.  To figure it out, you should look into how and why the
Ubuntu Atlas packages are compiled exactly, perhaps comparing to the
stock Atlas build instructions.

-- 
Andrew Piskorski <atp at piskorski.com>
http://www.piskorski.com/