[R] ATLAS for Pentium D and Pentium Duo Core?

[Jonathan Zhang]

Dear all,

  I wanted to use ATLAS to increase the computational speed of my
program. I have installed R in a straightfoward way with .exe file
(not building from source).

  However, after getting the P4 ATLAS Rblas.dll file from the CRAN
directory bin/windows/contrib/ATLAS, and replacing the default
Rblas.dll file in my R home directory under bin/, the speed actually
decreased by 3% compared with the default Rblas file!!

  So what am I doing wrong? Is the above the correct procedure for
using ATLAS? Or, is my machine not a Pentium 4 and hence the ATLAS
file that I got from CRAN is not appropriate?

  If the issue lies in the processor, then please kindly let me know
where to get the correct ATLAS file for the following computers:

 IThe first one is Pentium D 3.2 ghz, the second is a MacBook 1.83ghz
dual-boot and I am running R in windows.

  Thank you!

Jonathan Zhang

Marketing Division
Columbia Business School