well swap file up to about 4 gigs is about how much ram you have. after 4 gigs it really a over kill. And actually can cause your system to slow down.
if your going to run a swap partition on the same drive as the one you have your system installed really 4 gigs for 32 gigs of ram is plenty.
for one gig of ram the swap should be no smaller than 1024 but would go 2048 mb. you see the more ram you have.
here is a nice article on swaps the KISS method . http://www.control-escape.com/linux/lx-partition.html
you see with slow machine with little ram the swap area will be used more. so you could write a book on this. The double the ram is not true never will be for the home user. Second actually putting a swap partition on a separate drive will speed things up. Why do to the bus and seek time. the os is using the same drive and the swap is too. so things can slow down and will. since the 2.6 kernel you can just have a swap file also.
you have a slow machine 750 mb of ram you could use up to 2 gigs but not less than the amount of ram.
I am sure people will chime in on this. But come on for the home user.
Your not a server running 800 processes with 64 gigs of ram. I mean 32 gigs of swap for small processes for small processes.
Little hint when you ran puppy linux from windows with out a swap partition it created a swap file on the fly.