I have read on various posts that setting the swap file on a different partition speed up OS X a lot.
can anyone answer those questions for me
1- from a technical point of view why does it speed it up?
2- how big should the partition be?
3- I have 2 internal hard drives one with os 9.21 and the other with 10.1 , can i set the swap file on the 9.21 or should I partition either one of the drive to set a unique partition for the swap file?
4- how to set it up? ( idiot proof instructions,

)
Thanks