[R] Using R in parallel on a 2 processor machine
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon Nov 15 15:49:26 CET 2004
Try reading the rw-FAQ!
There is no way user processes in Windows XP can access all 4Gb of the
address space, but if you tune both R and XP correctly you should be able
to get above 2Gb in total. See the rw-FAQ for how to tune R.
Nevertheless, as you have already been told, it is a lot easier to do this
On Mon, 15 Nov 2004, Graham Law wrote:
> I have installed R (2.0.0) onto a two processor machine running Windows
> XP (these two processors have been split into 4 logical processors),
> with 4Gb of RAM. Rather than multi-threading, I wanted to run 2
> instances of R on the machine in parallel, which uses two of the logical
> processors. Unfortunately, R seems to be accessing a total of 1Gb of
> RAM, not taking advantage of 2 lots of 1Gb. This has led to memory
> problems, with one R process using the RAM, and the other one running
> into memory problems.
> Looking at previous posts on this issue, I have tried using gc(), to
> take back unused memory. This has allowed the two parallel processes to
> work, but has not given me access to the other 3Gb.
> Any help would be much appreciated into how R may run in parallel using
> more than 1Gb.
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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