No. I think this RAM is fine (or at least Crucial indicated it was compatible...). I did once try 16GB of 1866 Mhz and it was unstable. Kept getting kernel panics.
Neither display is 4K - the 2011 mini with HD3000 cannot drive even one 4K display. The max is 2560x1600. I have 2560x1440. 4K is 3840x 2160. TB2 or above is needed. 2011 mini only has original TB1/mDP connection + HDMI (max 1920x1200).
I don't care about games. I care about smooth UI (if possible), and lack of visual artifacts. Since upgrading to High Sierra, I was getting huge corruptions in window rendering - like massive jaggies across entire windows for a frame.
[doublepost=1538387218][/doublepost]UPDATE: After a second reboot, the UI is now smooth when dragging windows from one screen to another. Not sure what was wrong before.
Correct I've done a bit confusion about resolutions while typing due to hurry, however at this point if after reboot GUI is smooth, probably you have a third-party app that makes it laggy, try to check Activity Monitor when lagging.