Dear list,
I have noticed surprisingly big performance differences of runif()
between Windows XP and (Debian) linux on similar CPUs (Pentium D 3.0GHz
(WinXP)/3.2GHz (Linux)) and I wonder if there is a simple explanation
for the difference.
On a linux system (with a slightly better CPU and 1GB more RAM),
execution of runif() seems to consume about 80% more CPU time than on a
Windows XP system.
On a Xeon 2.7GHz (Debian) linux I have checked, that using the .deb -
i386 - Version of R instead of a self-build i686 - version has no
noticeable effect on speed.
Measuring CPU time with Rprof() instead of Sys.time()-differences yields
similar results.
Any hint is appreciated, please let me know, if the given information on
system/OS or the R output below is not sufficient.
Regards,
Martin Becker
------------------------ R - Output below ------------------------
Windows XP: (Pentium D, 3.0 GHz)
> version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 3.1
year 2006
month 06
day 01
svn rev 38247
language R
version.string Version 2.3.1 (2006-06-01)
> RNGkind()
[1] "Mersenne-Twister" "Inversion"
> t1<-Sys.time();for (i in 1:500) ttt<-runif(1000000);print(Sys.time()-t1);
Time difference of 57.969 secs
>
Debian Linux: (Pentium D, 3.2GHz)
> version
_
platform i686-pc-linux-gnu
arch i686
os linux-gnu
system i686, linux-gnu
status
major 2
minor 3.1
year 2006
month 06
day 01
svn rev 38247
language R
version.string Version 2.3.1 (2006-06-01)
> RNGkind()
[1] "Mersenne-Twister" "Inversion"
> t1<-Sys.time();for (i in 1:500)
ttt<-runif(1000000);print(Sys.time()-t1);
Time difference of 1.752916 mins
>
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