[R-SIG-Mac] Does 64-bit R use multiple cores?

[John C. Tull]

Simon,

Thanks for this information. Some better googling this morning  
revealed snow. I will also look into pnmath.

Regards,
John

On Nov 25, 2008, at 10:17 AM, Simon Urbanek wrote:

>
> On Nov 25, 2008, at 11:28 , John C. Tull wrote:
>
>> I thought Altivec was a ppc-only optimization. I'm pretty sure this  
>> does not apply to Intel systems, but maybe I'm wrong.
>>
>
> The Altivec part was incorrect but the multithreaded BLAS part was  
> correct. Replace Altivec with your favorite three-letter code for  
> Intel CPUs ;). [Not that Altivec matters in any way, since it  
> supports spfp only which R doesn't use ...].
>
> For more parallelization, see snow and pnmath by Luke Tierney.
>
> Cheers,
> S
>
>
>>
>> On Nov 24, 2008, at 10:23 PM, Kasper Daniel Hansen wrote:
>>
>>> It depends on the computations you want to do.
>>>
>>> R for Mac OS X uses Altivec which is a multithreaded version of  
>>> BLAS and lapack. What this means is that for any computations  
>>> involving matrix algebra, you do utilize multiple cores. Depending  
>>> on what you are trying to compute and how that computation is  
>>> implemented, this may prove to be just what you want or it may  
>>> have little to no effect.
>>>
>>> Kasper
>>>
>>> On Nov 25, 2008, at 15:24 , John C. Tull wrote:
>>>
>>>> Dear R-mac Users:
>>>>
>>>> I'm wanting to leverage an 8-core Intel Mac Pro for all of its  
>>>> computational glory. Looking over the mail list, it appears that  
>>>> the conversation on 64-bit builds of R has been about gaining  
>>>> access to memory beyond the 32-bit limit of 3.5 GB and not about  
>>>> multiple processors/cores.
>>>>
>>>> Does running 64-bit R only take advantage of one processor core  
>>>> at a time like the standard 32-bit R, or does it do symmetric  
>>>> multiprocessing (is this the right terminology?). If no, is there  
>>>> any possibility of doing this using X-grid or otherwise that  
>>>> someone can detail? I do have 10.5 Server if I have to go down  
>>>> that road.
>>>>
>>>> Thanks,
>>>> John
>>>>
>>>> --
>>>> John C. Tull, Ph.D.
>>>> Conservation Director
>>>> Nevada Wilderness Project
>>>> 8550 White Fir Street
>>>> Reno, NV 89523 USA
>>>> 775.746.7851 (office)
>>>> 775.224.2947 (mobile)
>>>> www.wildnevada.org
>>>>
>>>> _______________________________________________
>>>> R-SIG-Mac mailing list
>>>> R-SIG-Mac at stat.math.ethz.ch
>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>>
>>
>> _______________________________________________
>> R-SIG-Mac mailing list
>> R-SIG-Mac at stat.math.ethz.ch
>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>
>>
>