It did double my memory usage from 1G to 2G. I'm using python. I was shocked that the increase would be so big. Most of this data is in dict's.

So now I run the memory intensive stuff in 32 bit chroots:

http://www.gentoo.org/proj/en/base/amd64/howtos/index.xml?pa...

I made a little script to make getting into the chroot environment easy:

#!/usr/bin/env bash

linux32 chroot /mnt/gentoo32 /bin/bash -c "source /etc/profile;env-update;bash"