On 10 Feb 2003, Peter Dalgaard BSA wrote: > Laurent Gautier <[EMAIL PROTECTED]> writes: > > > ...sorry for the spam, but answers I get to my previous > > question suggest that I should specify that the > > machine has a *lot* of memory and should be able > > to the instanciation... > > > > Anybody with an IBM mainframe, R-1.6.2 and large > > matrices ? > > For whatever it's worth, that size does not appear to be a problem in > Linux. Takes a while, and a lot of memory, to get a summary of the > matrix though (I'm slightly puzzled by that: The memory footprint > appears to shoot up to 1.7G for something that is just working > on the columns of a 319M matrix?).
If the AIX you are using is 32 bit (I forget if they support 64) then you have to remember that, no matter how much memory you have, you are starting to run up against address space limits. It is only fairly recent Linux malloc's that are able to give a process more than 1GB of address space, and the way things are done when the 1G threshold is crossed is not necessarily very efficient. (1G is usually the point in the address space where the traditional heap has to stop because the shared library loader is mapped there). AIX will be different in detail but the basic issue is the same: 2^32 = 4G only leave you so much room to do the things the OS needs to do. luke -- Luke Tierney University of Iowa Phone: 319-335-3386 Department of Statistics and Fax: 319-335-3017 Actuarial Science 241 Schaeffer Hall email: [EMAIL PROTECTED] Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
