[rcxdude]

I would like to add one personal example where this isn't very true and is kind of painful: for a while I was running a windows system with quite a lot of RAM but not much disk space, enough that having swap space equal to my RAM significantly reduced the space available on an already nearly full disk. In linux this didn't represent a problem, because if memory was allocated and not used, it didn't count at all. However windows does not over-allocate: if you request memory there must be somewhere (swap or RAM) to put it. Without swap space this meant getting memory allocation errors with less than half of physical memory used, which was extremely annoying. I either needed to give up a huge chunk of my disk space (in practice I often needed 2x my RAM in swap to avoid memory exhaustion), or not be able to use all my actual RAM.

[kaslai]

Hmm, I was under the impression that Windows would also overcommit but it seems you're right. I've been in Linux land for too long I guess. If Windows doesn't have a physical place that can back the allocation, it will fail :(

Seems crazy to me given how useful it is.