Here is the promise: Your 4K TV can display:
- a 4k picture (3840×2160 aka “UHD” or 4096×2160 aka “4k cinema”)
- in full chroma (4:4:4 no subsampling)
- at 60hz refresh rate.
Does this technical mumbo-jumbo even matter? Why yes, yes it does if you want to use your TV as a computer monitor.
First, there are some requirements. You have to have a video card powerful enough to push the pixels at the required speeds. This means having something like an Nvida GTX 970 or newer. You also need to make sure your HDMI cable supports HDMI 2.0. Display port cables also work, but TVs that have display ports are rare. We have the requirements covered.
1. The 4k size: As computer people, we like having screen real estate. A 4k screen provides four times as many pixels. This allows a user to display four 1920x1080px windows on one screen. This is very efficient for development. Pretty straightforward, makes sense.
2. Full Chroma 4:4:4: What this means is that you get the full range of colors in a display. If you don’t have full chroma, then you’re going to have a problem with reading text. Below is an example of text displaying at 4:2:0 chroma. Look at the last two lines:
If you are using the TV as a monitor (like we do), this is crucial. If you aren’t displaying 4:4:4, then every text-based menu item in the operating system will have discoloration at best, or be unreadable at worst. This is a bad user-experience.
3. 60hz Refresh Rate: 60hz is the bare minimum standard. Monitors have been displaying 60hz as standard since at least Windows 95. If you drop the refresh rate down to 30hz, the mouse will CHUG slowly across the screen. Dragging windows will be painfully slow as they produce “tearing” during movement. This is a bad user-experience.
Lots of TVs promise a picture that meet the three requirements, but fail to deliver, resulting in a bad user-experience and a returned TV.
Do TV manufacturers really promise it? Yes, they do.
We tested two different TVs. The first was a Samsung UN40HU6950. Another was the LG 43UH6030. The specs for both indicated the TVs can display 4k pixels, at 4:4:4 chroma, at 60hz. This problem is not limited to a handful of bad apples. A quick Google search of “4k, 4:4:4, 60hz” will yield multiple forums of 20, 30, and 40 pages, each, of consumers going through their TV settings, investigating specs, and trying to determine if the TV actually does what it says it can do…for numerous models and manufacturers. Amazon ratings are also filled with consumers trying to determine if the TV is meeting its promise. We tested ours countless times, unplugging cables, power-cycling, etc.
Here is a photo of the TV settings for the Samsung. The promise is right there for the user to see on the TV itself. “UHD” = Ultra High Definition, which means it should be at least 3840x2160px. The 50P/60P is the refresh rate, where P means “progressive” as opposed to “interlaced”. And “4:4:4” is the chroma capability. Behold: