R help - Dec 2007 - Dual Core vs Quad Core

Dear R-users,

I use R to run spatial stuff and it takes up a lot of ram. Runs can take hours
or days. I am thinking of getting a new desktop. Can R take advantage of the
dual-core system?

I have a dual-core computer at work. But it seems that right now R is using only
one processor.

The new computers feature quad core with 3GB of RAM. Can R take advantage of the
4 chips? Or am I better off getting a dual core with faster processing speed per
chip?

Thanks! Any advice would be really appreciated! 

K.

       
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On Mon, 17 Dec 2007, Kitty Lee wrote:
> Dear R-users,
>
> I use R to run spatial stuff and it takes up a lot of ram. Runs can take
hours or days. I am thinking of getting a new desktop. Can R take advantage of
the dual-core system?
>
> I have a dual-core computer at work. But it seems that right now R is using
only one processor.
>
> The new computers feature quad core with 3GB of RAM. Can R take advantage
of the 4 chips? Or am I better off getting a dual core with faster processing
speed per chip?
>
> Thanks! Any advice would be really appreciated!
>
> K.
If I have my information right, R will use dual- or quad-cores if it's 
doing two (or four) things at once. The second core will help a little bit 
insofar as whatever else your machine is doing won't interfere with the 
one core on which it's running, but generally things that take a single 
thread will remain on a single core.

As for RAM, if you're doing memory-bound work you should certainly be 
using a 64-bit machine and OS so you can utilize the larger memory space.


----------------------------------------------------------------------
Andrew J Perrin - andrew_perrin (at) unc.edu - http://perrin.socsci.unc.edu
Associate Professor of Sociology; Book Review Editor, _Social Forces_
University of North Carolina - CB#3210, Chapel Hill, NC 27599-3210 USA

Hiding in the windows faq is the observation that "R's computation is
single-threaded, and so it cannot use more than one CPU". So multi-core
should make no difference other than allowing R to run with less
interruption from other tasks. That is often a significant advantage,
though.



>>> Andrew Perrin <clists at perrin.socsci.unc.edu> 18/12/2007
01:13 >>>
On Mon, 17 Dec 2007, Kitty Lee wrote:
> Dear R-users,
>
> I use R to run spatial stuff and it takes up a lot of ram. Runs can
take hours or days. I am thinking of getting a new desktop. Can R take
advantage of the dual-core system?
>
> I have a dual-core computer at work. But it seems that right now R is
using only one processor.
>
> The new computers feature quad core with 3GB of RAM. Can R take
advantage of the 4 chips? Or am I better off getting a dual core with
faster processing speed per chip?
>
> Thanks! Any advice would be really appreciated!
>
> K.
If I have my information right, R will use dual- or quad-cores if it's

doing two (or four) things at once. The second core will help a little
bit 
insofar as whatever else your machine is doing won't interfere with the

one core on which it's running, but generally things that take a single

thread will remain on a single core.

As for RAM, if you're doing memory-bound work you should certainly be 
using a 64-bit machine and OS so you can utilize the larger memory
space.


----------------------------------------------------------------------
Andrew J Perrin - andrew_perrin (at) unc.edu -
http://perrin.socsci.unc.edu 
Associate Professor of Sociology; Book Review Editor, _Social Forces_
University of North Carolina - CB#3210, Chapel Hill, NC 27599-3210 USA

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