[TriLUG] Hyperthreading and Xeons

[Joseph Mack]

Jeremy Portzer wrote:
> 

> Does this mean that I should treat it as a four-processor computer for
> the purposes of starting processes? 

sure, but remember that the extra 2 processors are memory bandwidth limited.
You can only use them effeciently if they are running on data in their local
cache. AFAIK the extra CPU core in each package is only there because it's cheap
to do and is good for marketing.

Try running  and timing 1,2,3 or 4 processes using bc to calculate pi to 
1,000,000 places

echo "scale=1000000;a(1)*4" | bc -l

Joe

-- 
Joseph Mack PhD, High Performance Computing & Scientific Visualization
LMIT, Supporting the EPA Research Triangle Park, NC 919-541-0007
Federal Contact - John B. Smith 919-541-1087 - smith.johnb at epa.gov