FWIW, I have a dual processor G5 Mac (not dual core... 2 separate, 2GHz
processors-- not even made anymore, so you might find a deal if trying to
save $$. If not, go for the octo-core Mac Pro--- 2 quad cores in one very
expensive box).

On my system I have found that with 5G RAM installed, I can either
1) launch an R64 session that is truly 64 bit R environment, and address
very large objects in RAM, or
2) do what has been described here and launch 2 sessions (in the command
line, or batch sessions, or 1 GUI and 1 CLI session) and get nearly full
speed out of both... a glance at the system activity  monitor shows both
processors pegged when I do this.

But if I use one regular R session, I still have a very responsive system
for other tasks. Good opportunity to use GnuCash to pay my bills....

I've never tried launching more than 2 sessions, since I only have the 2
cpus...



On 6/19/07, Matthew Keller <mckellercran@gmail.com> wrote:
>
> Hi Robert,
>
> Here's my 2 cents.
>
> 64-bit is a memory issue, not a speed issue per se. If a concern is
> increasing RAM (which is important in R since objects are stored in
> RAM), then you will want to get 64 bit if you plan on getting a
> computer with over 4GB RAM. I'm not sure about this (someone correct
> me if I'm wrong), but I think that windows has problems addressing
> that much RAM (surely the 64bit Vista is OK with it though... surely).
> Linux or Apple (the powermac) might be better bets if you're wanting
> to work with programs that use a lot of RAM. BTW, Intel does make 64
> bit chips now. They use them in macs.
>
> As for speed, go with multicore processors with as much GHz as possible.
>
> On 6/19/07, Robert McFadden <robert-mcfadden@o2.pl> wrote:
> > Dear R Users,
> > I hope that there is someone who has an experience with a problem that I
> > describe below and will help me.
> > I must buy new desktop computer and I'm wondering which processor to
> choose
> > if my only aim is to speed up R. I would like to reduce a simulation
> time -
> > sometimes it takes days. I consider buying one of them (I'm working
> under
> > Win XP 32 bit):
> > 1. Intel Core2 Duo E6700 2.67 GHz
> > 2. Dual-Core Intel Xeon processor 3070 - 2,66 GHz
> > 3. AMD Athlon 64 X2 6000+
> > Or simple Pentium 4?
> >
> > I'm very confused because I'm not sure whether R takes advantage
> dual-core
> > or not. If not, probably Athlon would be better, wouldn't be?
> > I would appreciate any help.
> > Rob
> >
> > ______________________________________________
> > R-help@stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
> --
> Matthew C Keller
> Postdoctoral Fellow
> Virginia Institute for Psychiatric and Behavioral Genetics
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
---------------------------------------
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mailto:dlvanbrunt@gmail.com

"If Tyranny and Oppression come to this land, it will be in the guise of
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