I've currently got a fairly decent system, with a few dependent services (Standard windows services, malwarebytes, windows defender, some others.) , and about fifteen browser tabs open, and I'm sitting at 1.5GB of RAM usage right now. And when I say windows 8, I'm assuming 8.1 as it makes no sense to not upgrade for free since so many of 8's issues have been resolved. I usually just lump 8 and 8.1 together. Nobody ever really refers to older OS's differently, like XP, XP2 or XP3, depending on the applied service pack, they just refer to it as XP and assume the service packs so I imagine eventually 8 and 8.1 will be the same.