Originally posted by: warhorse
Yeah, the partition for the page file is a requirement. Linux accesses the partition like a raw device, I think, so it doesn't use a filesystem or anything like that to store swap. As for setting up partitions, that isn't a requirement and it depends on your installer. IIRC, Red Hat would just stick everything in one partition, but Debian seperates /home. The reason for this I think is that if your OS dies, you can reinstall it and just remount your /home, leaving all of your local configurations and files intact.
I wouldn't think it improves performance or anything because it guarantees an expensive head seek to do stuff between partitions. With everything in one partition it is theoretically possible to get better response times by putting relevant data close to each other, although I don't know how well that works in practice.