On 22/03/2012 06:11, Peter Meilstrup wrote:
My guess would be that it's a matter of having swap space be a dedicated partition or fixed-size file (Linux, usually) versus swapping to a regular file that grows as needed (Windows and OS X, usually.) So if you defragmented your drive and set Windows to have a fixedsize swap file, it would probably behave more like your Linux machine.
There is far more to the topic than that, but the answer here appears to be a complete failure to supply the relevant information.
We haven't even been told the 'at a minumum' information required by the posting guide, so we do not know what architectures are in use. The messages suggest that 'Linux' is 32-bit and 'Windows' is 64-bit, in which case the tasks are simply not comparable. On 32-bit R on Windows I got the message about 3.4GB after 0.05 sec. Conversely, with 64-bit R on an 8GB Linux box with 16GB swap it swapped away for about 10 minutes. On a 32GB box it succeeded after 270s, typically using 8-14GB. The object SG tried to create is a bit over 7GB.
But Windows' memory management is notoriously slow, and R actually adds a layer on top to make it tolerable for routine use of R.
I have no idea why this was posted on R-devel: it did not involve R development nor programming, just a basic understanding of 32- vs 64-bit R.
Peter On Wed, Mar 21, 2012 at 10:14 PM, Spencer Graves< spencer.gra...@prodsyse.com> wrote:I computed "system.time(diag(30000))" with R 2.12.0 on Fedora 13 Linux with 4 GB RAM and with R 2.14.1 on Windows 7 with 8 GB RAM: Linux (4 GB RAM): 0, 0.21, 0.21 -- a fifth of a second Windows 7 (8 GB RAM): 11.37 7.47 93.19 -- over 1.5 minutes. Moreover, during most of that time, I could not switch windows or get any response from the system. When I first encountered this, I thought Windows was hung permanently and the only way out was a hard reset and reboot. On both systems, diag(30000) generated, "Error: cannot allocate vector of size ___ Gb", with "___" = 3.4 for Linux with 4 GB RAM and 6.7 for Windows with 8 GB RAM. Linux with half the RAM and an older version of R was done with this in 0.21 seconds. Windows 7 went into suspension for over 93 seconds -- 1.5 minutes before giving an error message. I don't know how easy this would be to fix under Windows, but I felt a need to report it. Best Wishes, Spencer -- Spencer Graves, PE, PhD President and Chief Technology Officer Structure Inspection and Monitoring, Inc. 751 Emerson Ct. San José, CA 95126 ph: 408-655-4567 web: www.structuremonitoring.com ______________________________**________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/**listinfo/r-devel<https://stat.ethz.ch/mailman/listinfo/r-devel>[[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
-- Brian D. Ripley, rip...@stats.ox.ac.uk 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 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
