On Wed, Jul 1, 2009 at 2:47 AM, Dirk Eddelbuettel <e...@debian.org> wrote: > > Rainer, > > On 30 June 2009 at 14:30, Rainer M Krug wrote: > | following a discussion on difference in speed of R between R and Linux, I am > | wondering: is there a howto to get the most (concerning speed) out of R? I > | am not talking about vectorisation and techniques in doing the analysis, but > | what should I look at when I want to get "the fastest R" on my computer - > | compiling myself? specific switches? compile libraries?, ... > > Did you look at R Admin manual and its Appendix B on Unix configuration?
Yes - thanks - but I seem to have skipped Appendix B.There it says: ### On most platforms using gcc, having ‘-O3’ in CFLAGS produces worthwhile performance gains. On systems using the GNU linker (especially those using R as a shared library), it is likely that including ‘-Wl,-O1’ in LDFLAGS is worthwhile, and on recent systems21 ‘'-Bdirect,--hash-style=both,-Wl,-O1'’ is recommended at http://lwn.net/Articles/192624/. Tuning compilation to a specific CPU family (e.g. ‘-mtune=core2’ for gcc) can give worthwhile performance gains, especially on older architectures such as ‘ix86’. ### I'll try it out when I compile R 2.9.1 and will see if it improves compared to the default values. Some more looking around, I found the following pages which might be helpful: GNU optimisation page: http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html Linux Review page on optimized gcc compiling: http://linuxreviews.org/howtos/compiling/ Gentoo Wiki CFLAG guide http://en.gentoo-wiki.com/wiki/CFLAGS There seems to be a lot to learn. > > And the end of the day, it will most likely depend on exactly what it is you > are trying to do, so you get back to square one and the need to profile, > benchmark, ... Yup - so much to benchmark and so little time... Cheers and thanks, Rainer > > Hth, Dirk > > -- > Three out of two people have difficulties with fractions. -- Rainer M. Krug, Centre of Excellence for Invasion Biology, Stellenbosch University, South Africa ______________________________________________ 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.