Sudden FPS Fluctuation

[Roynerer]

My first post! it's a cry for help ha!
Basically my problem is that the frame-rate whilst running certain games (right now I'm experiencing it with Super Mario Galaxy) jumps between 60 to 30 every 5-10 seconds, my configuration has stayed the same since I first downloaded the revision I use (3.5-476, found to run better than newer ones) and this has only started happening for the past couple of days.
I have my 3570k overclocked to 4.4GHz at the moment whilst my AMD7950 remains at stock (although I'm aware the emulator is mainly CPU intensive), I run it in fullscreen with an aspect of 1280x720, with no AA, on my TV screen, simply because higher resolutions almost literally look NO different and have always held a solid 60fps whilst playing this game in the past.
My average CPU temperature whilst running the emulator is around 38°C.

Halp please! any ideas what these fluctuations could mean?

If y'all need them..
Some SPECS:
CPU - Intel i5 3570k 3.GHz @ 4.4GHz
GPU - XFX HD 7950 3GB
RAM - 16GB Corsair Vengeance @ 1600MHz
OS - Windows 7 Professional x64

[admin89]

Set Framelimit to 60FPS + tick "limit by FPS" and try again

I run it in fullscreen with an aspect of 1280x720, with no AA, on my TV screen

You should use 4x Internal Res , no AA , 16xAF with Direct3D9 (which is faster thn Direct3D11) , you GPU is capable of doing this

because higher resolutions almost literally look NO different

higher resolutions -> downscaling effect -> much different
I always use 2.5x Internal Res(1600x1320) for Dolphin or 1440x1080 + 2x MSAA for PCSX2 on my laptop display (1366x768) , 2xIR (1280x1056) sucks