Not necessarily, I have an FX-9370 that idles at 40C with a clock of 5GHz (right now I have it at 4.44GHz normal and 5GHz turbo, but it idles pretty hot for a middle-class CPU), and an older Pentium 4 LGA 775 2.93GHz that idles around that too. i7s can get mildly hot if you don't have a heavy cooling system. If you really believe it's throttling then I would suggest starting with a Corsair H-80 ONLY IF it's an upgrade compared to your setup.
(edit) worded that horribly, If you can narrow it down to CPU throttling then you can either invest in a cooling system or lower your effective clock speed for more consistent temperatures; but the former will always be better.