Dear Brian, Mose, Peter and Stefan, Thanks a lot for your replies - the issues are now clearer to me. (and I apologize for not using the appropriate list).
Best wishes, Emmanuel 2008/11/19 Peter Dalgaard <[EMAIL PROTECTED]>: > Stefan Evert wrote: >> >> On 19 Nov 2008, at 07:56, Prof Brian Ripley wrote: >> >>>> I just read an announcement saying that Mathematica is launching a >>>> version working with Nvidia GPUs. It is claimed that it'd make it >>>> ~10-100x faster! >>>> http://www.physorg.com/news146247669.html >>> >>> Well, lots of things are 'claimed' in marketing (and Wolfram is not >>> shy to claim). I think that you need lots of GPUs, as well as the >>> right problem. >> >> Which makes me wonder whether R would be able to make use of this >> processing power, since the figures claimed by Wolfram are very probably >> for single-precision floats? (Am I right in thinking that R only works >> with double precision?) >> >> According to the nVidia Web site, the Tesla architecture is _ten times_ >> slower for double-precision operations than for single-precision, which >> makes it seem far less amazing than at first sight. >> > > It wouldn't be rocket science to add a single-precision data type to R, > it is just a large amount of work to get all details right, and noone > has found it worth the trouble. > > Probably more of a stumbling block is that GPUs traditionally have had a > rather cavalier attitude to floating-point standards. We have had our > share of problems with compilers that breaks the rules (or users setting > flags like -fast-math that allow rule breakage), and ensuing breakage of > user code and/or "make check", so I don't think it is viable to try and > get the GPU to take on all of R's computations. Special-purpose > computation, e.g. an R package interfacing to "libgpublas.so" or > whatever, is always a possibility, but that really goes without saying. > > -- > O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B > c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K > (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 > ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 > > ______________________________________________ > 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. > ______________________________________________ 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.
