For example when I start GTA IV the PSU starts making a loud noise and after 15 min the game freezes.Not only GTA IV but Crysis,Metro 2033,Need for Speed Shift...
That loud noise is the PSU fan starting to work at max speed probably. Always a bad sign.
What model of FSP PSU is that? If it's an older model it might be light on the +12V power rail.
And if's a few years old - PSUs can 'age' over time and loose the ability output it's full rated power.
Was there any crashing before you OC'd your CPU? Might be best to go back to stock and do some testing there - just to make sure it IS a PSU only problem.