Originally Posted by nifty
Are you changing it up to 256 or down to 256? (mine is set at 1024)
To basically summarize what the documentation says in more human terms, is since the GIMP can take up a lot of system resources (and with scrapbooking it does), you can reallocate how you're using your memory.
Memory is how your computer temporarily stores data it's using, and there are two types of memory.... RAM and swap (sometimes called virtual memory). RAM is the dedicated memory of the computer, and swap is a special partition on your hard drive that can be used like RAM when your RAM is maxed out.
By changing the tile cache to something like 256MB, you're basically telling The GIMP that when all the changes you've made are taking up more than 256MB in the memory, please move part of this to my swap partition so I don't run out of memory.
While utilizing the swap memory does boost performance in the sense that you're not going to be running out of memory and possibly losing your layout (I've had problems with crashing personally), however.... it does make your hard drive have to work harder, so if you're going to be doing a ton of scrapping, the most optimal thing to be doing is adding more RAM to your machine.