[R] Dismal R performance of Athlon moble CPU?
tlumley at u.washington.edu
Thu Jul 24 16:12:58 CEST 2003
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
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 Lumley Assoc. Professor, Biostatistics
tlumley at u.washington.edu University of Washington, Seattle
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