I tried to get 4K decode and display acceleration working (initially with a 1080p display) and this album summarizes my 'findings':http://imgur.com/a/zoX0s
After getting it 'working' on a 1080p display, I shifted to a professional setup that I have access to (a Sony VPL-VW1000ES), and am happy to report that 4K p 24 display worked from the AMD 7750 HDMI output (with decoding in cuvid mode using the GT 520). Will get in screenshots / pics with the projector later
What I am positive about
1. 4K decoding capabilities / content availability will be seeing better times as we move forward.
2. With Apple's push for high res displays at lower screen sizes, we should soon see 'retina-display' TVs and monitors, i.e, 4K resolutions at 30" and above.
Where I think industry could improve:
1. Tech companies: Don't call Quad FHD (3840x2160) as 4K in your marketing material. Toshiba, I am looking at you! You had a '4K' TV demonstration, and it was actually a 3840x2160 panel, and being driven by 4 HDMI ports to boot! Stop misleading consumers!
1. HDMI guys: What is the point of restricting'4K' to 4096x2160 at 24 Hz ? This is seriously short-sighted. Since we are going to such a high resolution, we might as well as get the full professional experience to the consumers [ 4096 × 3112 at 24 Hz]. Higher refresh / frame rates could be supported at the existing Quad FHD / 4096 x 2160 resolutions. This will definitely be coming soon, and we are going to see confusion between HDMI versions amongst the consumers.