Apart from the Nvidia Geforce GTX 960, 970, and 980, all other video cards from Nvidia, AMD, and Intel have HDMI 1.4 or less.
This is very significant because HDMI 1.4 can only do 30 frames per second at the 3840×2160 resolution while HDMI 2.0 can do 60 frames per second at 4K resolution.
Additionally, these new HDMI 2.0 video cards also have a H.265 (HEVC) video decoder as opposed to the H.264 video decoder of previous generations.
Please note that Nvidia initially made an error in the specifications for the 970. It’s slightly less powerful than initially represented. There is now a class action lawsuit in regards to this error.