Thank you very much, Profs. Ripley and Peng! It corrected a big misconception in my mind.
By the way, does the Sun Forte 7 compiler produce faster R than the GCC 3.4.1 compiler (which we use)? Jason --- Prof Brian Ripley <[EMAIL PROTECTED]> wrote: > On Tue, 7 Sep 2004, Roger D. Peng wrote: > > > Are you using an optimized BLAS for both builds? That's one > > possibility. Also, 64-bit builds use up more memory initially > since the > > pointers are bigger. I've tried both 64-bit and 32-bit builds on > > Sparc/Solaris and haven't seen any slowdown. > > It uses more memory at all times and so gc() takes longer. There > *is* a > slowdown, for example 90 vs 80 secs for a run of R-devel's stats-Ex.R > (for > either Sun's Forte 7 or gcc 3.4.1 compilers). But `25-30% slower' is > unexpected and needs investigation. > > The only difference between 32-bit and 64-bit versions of R on > Solaris > will be the size of the pointers and (probably) less efficient PIC > code. > There is no reason to expect a performance boost with 64-bit > applications: > they have to do more work and are only worthwhile if you need the > address > space (in memory or also on disc as 64-bit applications use large > files > natively). > > > > Jason Liao wrote: > > > > > Hello, everyone! I guess no one is still using R on Sun Sparc > these > > > days. But our department has a (pretty new) two-CPU Sun server. > We > > > recently compiled R as a 64 bit application and expected a > performance > > > boost. But it runs 25-30% slower than the 32 bit version of R. > Anyone > > > knows why this is so? Thanks! > > -- > Brian D. Ripley, [EMAIL PROTECTED] > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 > > ===== Jason Liao, http://www.geocities.com/jg_liao Dept. of Biostatistics, http://www2.umdnj.edu/bmtrxweb University of Medicine and Dentistry of New Jersey phone 732-235-5429, School of Public Health office phone 732-235-8611, Cancer Institute of New Jersey office moble phone 908-720-4205 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html