How can a 4K display with 60 Hz refresh rate operate at a higher refresh rate at lower resolutions?

Question

I know there is not yet a 4K monitor offered for consumers that is 144 Hz, but are there any 4K monitors out there that offer a separate mode that runs at a higher refresh rate with a lower resolution, because supposedly this one does:

PRISM Korea M280PU Pro

It supposedly offers an option to run full HD resolution at 144 Hz but also an option to run 4K resolution at 60 Hz. I've never seen an option like this before. I thought something with that many pixels and a refresh rate of 60 Hz would be limited to just 60 Hz regardless of the resolution.

Is this really even technologically possible?

Answer 1

There are multiple issues stopping you from running 4 K at 144 Hz. There's a bit of guesswork here, but

1. They tested and worked out the panel would do 1080p at 144 Hz. There are examples of panels with slower refresh rates that would overclock to 144 Hz, like some variants of the Yamakasi Catleap.

2. The bottleneck for faster refresh rates might not be 'just' the panels – there's no common standard that would do 4 K at 120 Hz or better (dp 1.3 systems are just coming out), so there's no practical purpose to monitor hardware that does it.

3. There's no controller chip that would do 4k120 or better, but someone figured there's a market for different refresh rates if you drop resolutions. My guess is they found the panel controller has the power to do 1080p144.

4. Monitors can do different refresh rates already – you often drop down to 4k30 on older dp connections, but go back up to 60 as needed. The bottleneck is likely the controller.

In theory, I'd suspect the same panel could do 4 K 144 with the right controller and interface. Since the interfaces and controllers are non-existent, it makes business sense to sell a monitor with high refresh rates (for gamers) and high resolution (for entertainment, I suppose) and let people pick between them.