The 780GTX is what you want with that media. The new 780TI would be an ideal choice.
Only 5K may require more VRAM than the currently offered 3 GB.
What about the amount of VRAM?
As a rough guide, how much VRAM should be installed on the video card, think along these lines:
- For SD material, 1 GB is enough
- For HD material, go for 1 - 2 GB
- For 3K or 4K, go for 2 - 4 GB
- For 5K+, go for 4 - 6 GB
Keep in mind that the requirements can vary significantly, depending on the complexity of the timeline. If it happens that the VRAM is depleted (not enough memory), hardware MPE is automatically turned off rather ungracefully and stays off for the rest of the encoding. If you use two video cards in CC, each card uses its own memory and cannot use the memory on the second card. The encoding process works like this: Frame 1 rendered on card 1, frame 2 rendered on card 2, frame 3 rendered on card 1, etc. If either card runs out of memory, again hardware MPE is turned off. Simply put, two video cards with 1 GB each can not be treated as a single card with 2 GB, so the risk of turning off hardware MPE automatically is bigger with these two cards than with a single card.