[R-SIG-Mac] New intel based laptops

Simon Urbanek simon.urbanek at r-project.org
Thu Jan 26 15:49:43 CET 2006

On Jan 26, 2006, at 5:11 AM, Ken Beath wrote:

> On 26/01/2006, at 6:36 PM, Simon Urbanek <simon.urbanek at r- 
> project.org> wrote:
>> As of performance, don't hold your breath, Core Duo is fast for  
>> daily use, but not particularly good at computing like BLAS.
> According to Apple, the Intel iMacs have specFP performance twice   
> that of the G5 iMacs they replace. Definitely slower than the quad   
> powermacs but will make most most people happy.

SPECs are one thing, reality another, we have learned that many times  
over. I guess it is public information now that those Macs are now  
available at every Apple store where you can test this for yourself,  
but BLAS is actually slower on Core Duo than on a single G5 of the  
same clock speed (and this includes using both cores of the Intel  
with ptATLAS so you can test it on any computer with Darwin). This is  
in fact consistent with the P4 BLAS performance in general (no one I  
know considers P4 seriously for computing - if x86 then AMD). Some  
other (non-BLAS) tests show faster speed than G5 possibly due to the  
large caches and the Intel chip blows away G5 in tasks like sorting  
of large vectors.

Apart from R performance the machines feel fast - the dual core is  
definitely a win if you can keep it busy (compilation, threaded tasks  
etc.). My next laptop will be a MacBook, but I'll keep my iMac G5 for  
a while ;).


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