Swap File - Where to find and how to edit?

Question

I have a game with requirements I all meet/exceed, but one is unknown to me. And that is the need for a 1GB swap file. I'm not sure where to check to find it, nor how to edit/make one if it's not big enough.
I'm a bit of a dunce when it comes to these sorts of things, so any help would be appreciated.

Answer 1

Unix will "page" before it "swaps". Applications require memory for two reasons: (1) they need to load the application program code (or at least some of it) into memory, and (2) as you do things with the program, it needs some memory space for all the data your program is dealing with which is NOT application program code.
As more memory is needed, the Unix kernel will begin by taking memory listed as being "free" (memory that nothing is using - and btw it's normal for a good Unix operating system to try to keep that number low... you paid for the memory so it might as well do something for you and Mac OS X will try to find a user for it.)
As the "free" / available memory is depleted, the kernel will begin stealing memory from the "inactive" list (memory which was previously used by some other application, but that application doesn't seem to want to use it right now -- usually because it is no longer running. It doesn't immediately return memory to the "free" list because odds are good you may re-run the application and the system will be faster if the code that would otherwise have needed to be read in from disk is already in memory.)
As the "inactive" memory is depleted, it will then begin "paging" applications which are still technically in memory, but seem to be idle right now. It doesn't drop the "data" being managed by those applications... instead it just frees up memory used by that application's code. It does this (as opposed to freeing memory used for data) because the code can easily just be re-read in from the disk drive (no need to 'save' the memory before freeing it because it's already on disk.)
Only when all else fails (no 'free' memory, no 'inactive' memory, and no idle applications that can have their code pages dropped) will the system begin to 'swap' (swapping is the slowest way of creating more virtual memory.)
Unless you have a very small amount of real memory (in which case just upgrade... RAM is cheap!) or have a LOT of other active applications running on your system at the same time which also are demanding a lot of memory (in which case, just 'Quit' the other applications before starting your game), then your performance issue is not likely caused by a lack of memory.