2k is not very high resolution, 4k is. 780 Ti is going to be better at 4k because the 690 will run out of VRAM and tank. Even the 780 Ti will run out of VRAM in some games at that resolution. But its not going to be all that great at 4k compared to other modern offerings like Fiji and GM200. If you're thinking of buying one just post the deal here instead directly and see if its worth it