[R] R performance: different CPUs

[Thomas Lumley]

On Wed, 5 Apr 2006, Jasjeet Singh Sekhon wrote:

>
> Hi,
>
> 64bit CPUs, such as opterons, help significantly with large databases
> or if you are running multiple processes.  But there is a speed
> penalty if you are not.

This would be true of 64-bit builds of R, not 64-bit CPUs.

On a 64-bit processor you can usually run either 64-bit or 32-bit builds 
of R, and the 64-bit one will be able to access more memory but will be 
slower.

This doesn't mean that a 32-bit build of R on a 64-bit processor will be 
slower than a 32-bit build of R on a 32-bit processor.

 	-thomas

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