[R-SIG-Mac] How to Speed up R on the G5

[Thomas Lumley]

On Mon, 7 Feb 2005, Jake Bowers wrote:
>
> My first question is how to play with these different versions without
> breaking my production version? That is, I don't want to have to
> delete my currently working build of R-patched each time I want to run
> a speed test.

You can build R without installing it, as long as you don't want to use 
the GUI.  For example, I have the current development version of R in 
~/R-devel/R and version 2.0.0 installed in /.

Then use

  ~/path/to/this/version/R CMD INSTALL thepackage

to install the package.  Make sure you don't have an .Rprofile that would 
put all the packages in the same place.


> My second question is whether there are ways other than using
> --with-blas="-framework vecLib", to take advantage of what I thought
> was the power of the G5 (or dual G5s in my case).

I haven't found anything very impressive yet (this is on an iMac G5, so 
with much lower bus speed).

I am planning to test the IBM (Absoft) compilers when I get time.  In the 
past people have found that a good Fortran compiler can speed R up 
noticeably (eg on Solaris).


 	-thomas