I suspect that it was Intel's marketing department, after a few beers at the local bar...
;-) Regards, Marc 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? > > > Cheers > Joris > > 2010/6/29 Uwe Ligges <lig...@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 >>> >>> >> > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
