So for the past few months I've been experiencing what seems to be weird frame rate drops in games where I had perfect 60+ before. Started looking into things with a frame counter and it got weirder. My frame rate doesn't actually drop, it just looks like its suddenly running at about 25 fps, while still having over 60 on fraps. It comes and goes for random amounts of time and no video driver updates or reboots seem to fix it. Anyone seen anything like this before?

Well, I've hit some snags like this, before. Honestly, the thing that helped me was defragmenting my hdd(s). I would go that route, see if it helps.

Need to see your complete PC specs, and which games you've noticed this on and graphics driver info.

I have that exact problem, its overheating. CPU is probably hitting 80C+, I am about to redo the entire cooling system in the PC. Make sure all the vents are clean of dust and that the heat fins on the CPU heat sink aren't clogged with dust.

::EDIT:: To clarify, when the CPU starts getting too hot it will start changing things to cool itself down, it can cause wierd FPS lags but no actual frame drops. Its strange I know.

Sounds like a heat issue, but that's just a guess based off not-alot of information.