i welcome the post. even though most of my stuff runs on 64bit, i actually do have a few 32 bit systems here and there. I never knew. Because as the op mentions it's not written anywhere _obvious_.

another thing I didn't realize was that because of the memory mapped systems which i guess is fine performancewise it's hard to estimate memory usage on a machine. from what I understand there is no possibility to limit the memory usage. Which means that the only way you can limit the amount of memory used is by keeping the size of the database below your memory. quite important things to know imho.

here's an interesting post mentioned in the comments: http://www.zopyx.com/blog/goodbye-mongodb