[R] Use of processor by R 32bit on a 64bit machine

[Joris Meys]

*slaps forehead*
Thanks. So out it goes, that hyperthreading. Who invented
hyperthreading on a quad-core anyway?


Cheers
Joris

2010/6/29 Uwe Ligges <ligges at statistik.tu-dortmund.de>:
>
>
> On 29.06.2010 15:30, Joris Meys wrote:
>>
>> Dear all,
>>
>> I've recently purchased a new 64bit system with an intel i7 quadcore
>> processor. As I understood (maybe wrongly) that to date the 32bit
>> version of R is more stable than the 64bit, I installed the 32bit
>> version and am happily using it ever since. Now I'm running a whole
>> lot of models, which goes smoothly, and I thought out of curiosity to
>> check how much processor I'm using. I would have thought I used 25%
>> (being one core), as on my old dual core R uses 50% of the total
>> processor capacity. Funny, it turns out that R is currently using only
>> 12-13% of my cpu, which is about half of what I expected.
>>
>
> An Intel Core i7 Quadcore has 8 virtual cores since it supports
> hyperthreading. R uses one of these virtual cores. Note that 2 virtual cores
> won't be twice as fast since they are running on the same physical core.
> Hence this is expected.
>
> Uwe Ligges
>
>
>
>> Did I miss something somewhere? Should I change some settings? I'm
>> running on a Windows 7 enterprise. I looked around already, but I have
>> the feeling I overlooked something.
>>
>> Cheers
>> Joris
>>
>> sessionInfo()
>> R version 2.10.1 (2009-12-14)
>> i386-pc-mingw32
>>
>> locale:
>> [1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United
>> States.1252    LC_MONETARY=English_United States.1252
>> [4] LC_NUMERIC=C                           LC_TIME=English_United
>> States.1252
>>
>> attached base packages:
>> [1] grDevices datasets  splines   graphics  stats     tcltk     utils
>>    methods   base
>>
>> other attached packages:
>> [1] svSocket_0.9-48 TinnR_1.0.3     R2HTML_2.0.0    Hmisc_3.7-0
>> survival_2.35-7
>>
>> loaded via a namespace (and not attached):
>> [1] cluster_1.12.3 grid_2.10.1    lattice_0.18-3 svMisc_0.9-57
>>  tools_2.10.1
>>
>>
>



-- 
Joris Meys
Statistical consultant

Ghent University
Faculty of Bioscience Engineering
Department of Applied mathematics, biometrics and process control

tel : +32 9 264 59 87
Joris.Meys at Ugent.be
-------------------------------
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