17 Mar 2020, 21:38

4K Disappointment

tl;dr - before going down the 4K path, make sure your graphics hardware is capable of driving your display at full spec.

My old faithful Dell U2412 monitor recently started playing up. It is my main ‘work from home’ monitor and I needed to get work done, so I rather hastily found a replacement. I thought to myself “hey, 4K has been around for ages and prices are reasonable so may aswell grab one of those”. I settled on a Samsung LU28E590DS capable of upto 3840x2160@60hz. I plugged it in a cranked the resolution right up - sweet! Looks gorgeous. I ended up enabling 200% scaling to make the text readable (unfortunately fractional scaling is not officially supported yet in Gnome).

I quickly realised that the interface was noticeably laggy - like everything had been dipped in molasses. My first inclination was that my graphics adaptor was struggling at 4K resolution, but after some research into the wonderful world of computer display graphics I came to the conclusion that the issue was in fact the refresh rate - my hardware (Intel HD530 iGPU) was only capable of outputting at 4K@24hz instead of the 60hz I’d been used to. That was annoying but I thought to myself, “oh well I’ll just drop the resolution down to something that can output at 60hz”. Unfortunately I then struck the problem of non-native resolution and the blurriness that results from scaling; for me this was an unacceptable tradeoff - in my opinion worse than the lower refresh rate! Again I naively thought “4K has been around for ages, surely I can grab a low end graphics card that will output 4K@60hz!?” Alas, no. Well technically, yes, but only Nvidia it seems. I’m running Linux and, unless you’re a gamer (which I’m not), Nvidia’s drivers are not worth the hassle IMHO.

As I’ve now discovered, until relatively recently only DisplayPort has been capable of outputing 4K@60hz. However that adaptor is far less common (on PC hardware at least) than HDMI. The story with HDMI is that it was limited to 4K@30hz until v2.0 of the HDMI spec, which is only included on higher end graphics cards and motherboards!

My options are this stage:

  • put up with 24hz (what I’m currently doing)
  • buy a standalone graphics adaptor which comes with Displayport and/or HDMI 2.0 - PROS: flexibility CONS: expensive, noisy
  • replace my CPU + motherboard with something more recent, that includes onboard Displayport and/or HDMI 2.0 - PROS: updated CPU + chipset, quiet CONS: inferior graphics capability compared with standalone