Maximum amount of memory

On 21 Mar 2005, at 4:42 pm, marvena at tin.it wrote:

Hi,
I have a problem:I need to use the maximum amount of memory in order to
perform a very tough analysis. By purchasing the suitable computer, what's
the maximum amount of memory obtainable in R?

Assuming that R is happy to use 64-bit memory pointers, the limit will be 
your wallet.

I believe there are still some limits on sizes of individual objects, such 
as C and Fortran code that uses int or INTEGER to hold dimensions.

Many packages will definitely have problems: for example, the survival 
package cannot correctly handle a design matrix with more than 2^31-1 
elements, no matter how much memory it has.  I don't know how much of the 
internal R code would also break when vectors have more than 2^31-1 
entries.

Now, 2^31-1 entries in a numeric matrix is 16Gb in one object, so your 
wallet is still likely to be the practical limit.

 	-thomas

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