they are both great cards, and it depends on your usage, but for games, the 770 is usually a tiny faster, not much. they can both run any game on ultra 1080p. the 280x has more vram, so if you game on multiple monitors or at resolutions higher than ~1440p or 1600p go for the 280x, if not then the 770. but, check out benchmarks for the games you play, the 280x may be faster.