The R9 is a very expensive card and beyond my budget :-(
I tried a MSI Radeon HD 5450 card with my 4k monitor and I can run it at 3840 x 2160 (via HDMI). Even though the spec says HDMI is limited to 1920 x 1080 (it picked it when I did auto-detect on CCC) :-)
I don't understand why I see negligible performance differences between my Radeon HD 5450 1GB (64bit) and the Radeon R7 270 2GB (128bit).
Looking at the specification - the R7 240 should have outclassed the HD5450 in every way.
Both cards struggled with 4k YouTube videos. They both dropped similar number of frames etc..
So I wonder, what is the benefit of a faster more expensive graphics card? Are all the benefits for gamers rather then 4k users?