Nowadays, DDR3 RAM so cheap, hey, why not? But aside from the geeky cool factor of maxing out my motherboard, having all that extra RAM means tons of extra file cache. This is excellent for repeatedly grepping through gaggles of source, header, and other txt files searching for various strings without having to reread from the hdd each time. Also, I use a RAM drive to do a bunch of temporary operations, such as zipping or unzipping files, thus saving on wear and tear on the hdd.

