I have a 670 and I was thinking in a slightly better graphics card. The options I have in mind are: 960 4gb and 280x. I am attracted to the fact that the 960 is quiet, has low temperature and low power consumption, plus compatibility with directx12. I believe, however, that the 128-bit bus leave it well behind the 670 and 280x. What do you recommend? These cards will be sufficient for games of "next-gen"? Thank you!