so ive had my laptop for 3 years now, it used to run games just fine (civ v, bf3, skyrim etc.) but now when i play them for more than around 5mins my fps drops drastically to make the game unplayable. It stays like this for awhile then gets fine for 10 seconds then goes back to complete ass. anyone help me figure this out?
get a can of compressed air and blow out the vents.
Also, after 3 years I imagine your batter doesn't hold much charge anymore, right? In those cases it starts to generate a lot of heat, needlessly so. So, if you're running on AC power, pull the battery out and see if that helps the issue a bit.
Also, make sure that your ambient room temperature isn't too high. And as a last measure you can get a laptop cooling pad. They provide some surface cooling and can help dissipate some of the heat the cooling heat sinks cannot always get to. (That is if you don't already have one)