Good Lucky. Just remember that overclocking is not the answer for every game, and/or situation. You may do more harm than good. I have seen way too many machines overheat using this option, and die without the proper stress test being done. Therefore I never use this option. I’d rather buy a better CPU/Motherboard than have to risk that option, and wind up getting one anyway.
If you think Crysis looks, and feels good now, wait until you get a better system when you’re ready.
There is no way to change the OpenGL, or Direct 3D settings on this game. It simply doesn’t offer it. What you see in the video options is all you get.