On Tue, Oct 5, 2010 at 5:21 PM, Carrie Li <carrieands...@gmail.com> wrote: > I am sorry that it has been couple days. > I've read the website you provided below, but still don't quite know if this > is doable. > The maximum vector length is 2^31-1, so here is what I tired, and it > returned errors as below. > > > P=20000 > D=matrix(rep(0, P*P), nrow=P) > > Error: cannot allocate vector of size 1.5 Gb > In addition: Warning messages: > 1: In as.vector(data) : > Reached total allocation of 1535Mb: see help(memory.size) > > On the manuals, it says "32-bit OSes by default limit file sizes to 2GB ", > so why P=20000 is not working here ?
Every double value (e.g. 0) needs 8 bytes. So the total memory needed for that matrix is 8*P*P = 3.2e+09 bytes = 3.2e+09/1024^3 Gb = 2.98Gb. Now, in order to do anything useful you also need space for creating an internal copy or two of that object. That is, you basically need 2-3 times more *free* (and *contiguous/non-fragmented*) RAM than that to do anything useful. /Henrik > > Thanks for any helps. I appreciate. > > > On Sat, Oct 2, 2010 at 12:22 PM, Marc Schwartz <marc_schwa...@me.com> wrote: > >> On Oct 2, 2010, at 11:14 AM, Carrie Li wrote: >> >> > Hi everyone, >> > >> > If I run on a 64-bit R, what is the maximum matrix size that it can >> handle ? >> > Is a matrix 20,000 x 20,000 possible on 32 bit ? >> > Thanks for answering! >> >> >> A matrix is a vector with 'dim' attributes. The maximum vector length is >> 2^31 - 1 and that does not change between 32 and 64 bit R. The primary >> advantage of 64 bit R is the larger memory address space. >> >> See: >> >> >> http://cran.r-project.org/doc/manuals/R-admin.html#Choosing-between-32_002d-and-64_002dbit-builds >> >> HTH, >> >> Marc Schwartz >> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.