[R] No performance increase from dual-core processors?

[Adam Petrie]

Hey all,

I was planning on getting a new computer for the new year to help with 
my dissertation research, and recently had an opportunity to compare the 
performance of my 1.6 GHz Pentium M laptop, and a 2.8 GHz dual-core 
Pentium processor (both running WinXP professional 32-bit).  I run a lot 
of long simulations, so I was hoping to get something that would speed 
them up.  I ran a few quick computation tests (e.g.  generating 500,000 
normals), and found the performance increase of the 2.8 dual-core over 
my 1.6M laptop to be negligable (and in fact sometimes slower).  One 
thing I did notice that if I look at the CPU usage of my laptop when 
it's performing the simulations the laptop is at about 100%, while the 
dual-core reaches 50% (and seems to refuse to go higher than 50% no 
matter what).  Of course if I load up 2 instances of R I can get them to 
run the simulations simultaneously in about the same amount of time, but 
this doesn't help me get to the end of a very long simulation quicker.  
This got me thinking that no matter what kind of processor I get, I'm 
not going to be getting a large speed increase over what I already 
have.  Does anyone have any insight into various setups/processors that 
would help me speed up my work (e.g. maybe run R through linux, Pentium 
extreme edition, etc)?

Thanks in advance,

Adam Petrie
Rensselaer Polytechnic Institute