It may be overkill, although RAM is so cheap these days theres really no reason to not buy 4GB, as you can find 4GB of RAM for as low as $73.I have 4 gigs of ram but i only have 3 installed for the same reason. You honestly don't need 4 gigs for anything. most of the time its overkill. it really depends on what you use your computer for.
Is it possible to build a multiple PC's and link them together in line to get a sort of super computer effect but on a smaller scale? If so, then how would one go about doing that?
I have 4 gigs of ram but i only have 3 installed for the same reason. You honestly don't need 4 gigs for anything. most of the time its overkill. it really depends on what you use your computer for.