FPS Drops and Stuttering

[BrownKnight]

I have an OC'ed FX-6300 (4.5ghz) and an r9 270 (1130/1500mhz) but when i try to play super mario galaxy 2, my game stutters and I get low fps (dips to 40). When i play super smash bros I also get FPS drops but then it works fine when the actual fighting starts. What's weird though is that when i take a look at MSI afterburner, both my cpu and gpu usage is below 60%!