[R] Use of processor by R 32bit on a 64bit machine
marc_schwartz at me.com
Tue Jun 29 16:17:46 CEST 2010
I suspect that it was Intel's marketing department, after a few beers at the local bar...
On Jun 29, 2010, at 9:09 AM, Joris Meys wrote:
> *slaps forehead*
> Thanks. So out it goes, that hyperthreading. Who invented
> hyperthreading on a quad-core anyway?
> 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.
>>> R version 2.10.1 (2009-12-14)
>>>  LC_COLLATE=English_United States.1252 LC_CTYPE=English_United
>>> States.1252 LC_MONETARY=English_United States.1252
>>>  LC_NUMERIC=C LC_TIME=English_United
>>> attached base packages:
>>>  grDevices datasets splines graphics stats tcltk utils
>>> methods base
>>> other attached packages:
>>>  svSocket_0.9-48 TinnR_1.0.3 R2HTML_2.0.0 Hmisc_3.7-0
>>> loaded via a namespace (and not attached):
>>>  cluster_1.12.3 grid_2.10.1 lattice_0.18-3 svMisc_0.9-57
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