Chris Rowson wrote: > [...] > I've always used 32bit edition on servers myself. I've heard horror > stories about perl scripts using twice as much memory under 64bit etc, > etc.... I've never tested PAE with more than 4GB of RAM - I had heard > about the single process limitation, but as I only had 4GB to play with, > I've never had the opportunity to hit that limit!
Hello, Chris. In fact you can only alloc() 2GB in a contiguous block if you have 4GB RAM installed. You can get somewhere near 3GB in total per process if you don't care about memory fragmentation with 4GB RAM installed. Things improve quite a lot with 8GB installed, but you still can't get >4GB per process using PAE. For many programs that's not a problem, and you're right about 64-bit doubling the size of memory usage in certain situations. Actually, I don't think 64-bit is worth it unless you have very BIG memory problems to solve. PAE is quite good if you want to run multiple instances of programs that have < 4GB memory footprints. Bye, Tony. -- Dr. A.J.Travis, University of Aberdeen, Rowett Institute of Nutrition and Health, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, Scotland, UK tel +44(0)1224 712751, fax +44(0)1224 716687, http://www.rowett.ac.uk mailto:[EMAIL PROTECTED], http://bioinformatics.rri.sari.ac.uk/~ajt -- ubuntu-uk@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/