Michael Stapelberg's blog was a source for me when I bought my Dell UP3218Ks specifically for usage with Linux. A great resource!

The article mentions that "it (the Dell UP3218K) needs two (!) DisplayPort cables on a GPU with MST support, meaning that in practice, it only works with nVidia graphics cards."

I would like to tell people here that this is not true in my experience (which might be related to advances in amdgpu and/or linux in general): I'm running one Dell on a Vega (64) Frontier Edition and one on a 6900XT, both on Linux 6.3 with the amdgpu driver. It sets up correctly, using DP TILE extension, so both cables used, 7680x4320@60hz.

Also I would like to add (subjectively) that nothing beats the display quality of these screens. It's literally life/eye-changing.. insanely nice, sharp. I could never go back to sub ~200ish DPI displays.