upper memory limit

Tim Roberts timr at probo.com
Tue Aug 10 07:22:59 CEST 2004

Peter Wilkinson <pwilkinson at videotron.ca> wrote:
>Why do you say that  single process is limited to 2 Gig?  I believe that on 
>windows a single process can run with to 32 bits addressed or 4 Gig of 
>space. I have run R with over 2 Gig of memory.
>Why would python be limited to 2 Gig (including overhead)? I don't see that 
>python should be any different.

(I responded privately, but thought I should register the answer here,

No, a user-mode process in Windows is limited to 2GB of address space.
Addresses 80000000 and larger are kernel space.  You can change the
threshhold to 3GB by using the /3gb boot.ini switch, but few do so.

You can certainly have more than 2GB of physical RAM in your machine, but a
single process cannot use more than 2GB at a time.
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.

More information about the Python-list mailing list