strange fps for decent system

[flattopman]

I recently just purchased a system containing an r9 285 and an amd fx-6300 and while i was playing non intensive games like league and cs go the fps seemed non consistent and both games only running at about 120 fps and periodically droping to 60 and even lower. so i checked msi after burner and my graphics card usage was going up and down but rarely reaching max and the same with my cpu and ram so i was wondering why my fps is so low.