DJBarry: I really don't think he needs to overclock an i7 4770K, especially for Twilight Princess.
Darksin: I think maybe your problem is the shadercache being generated or the "Hyrule Field" issues that make the game difficult to run. You can try running OpenGL with that graphics card, keep the Internal Resolution at 2x or lower, because this game uses EFB2Ram, higher IR really hurts the framerate. Vertex Streaming Hack helps on this game as well, so have that on, should have no negative effects. If my computer can handle it, yours can too, yours is pretty much identical (or better, in case of processor) to mine.
Darksin: I think maybe your problem is the shadercache being generated or the "Hyrule Field" issues that make the game difficult to run. You can try running OpenGL with that graphics card, keep the Internal Resolution at 2x or lower, because this game uses EFB2Ram, higher IR really hurts the framerate. Vertex Streaming Hack helps on this game as well, so have that on, should have no negative effects. If my computer can handle it, yours can too, yours is pretty much identical (or better, in case of processor) to mine.