[R] Dismal R performance of Athlon moble CPU?

[Thomas Lumley]

On Wed, 23 Jul 2003, Jason Liao wrote:

> Thanks for Prof. Ripley and Andy for your technical explantion. It
> seems that that the real CPU speed has not advanced as fast as these
> Ghz or other performance indicator suggest.
>
> Yes, my program is totally CPU intensive.
>

It may not be even if you think it is. Note that much of the speed
increase that ATLAS achieves comes from optimal use of various levels of
cache. It's quite possible that your code is actually limited by memory
bandwidth.

In any case, I think R is often limited by integer rather than
floating point peformance.  Back in the days when I timed things in R, its
relative performance across PCs and Sparcs suggested that floating point
wasn't a big deal.


	-thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle