Lately, when working from home, IntelliJ would slow down and act like it’s running on a Pentium 2 instead of an i7… Simply scrolling through an XML file is problematic with intermittent pauses. And only when working from home, at the office everything worked fine!
Problem solving mode on. Activity monitor. Run glances. Change keyboard, mouse, unplug USB hub altogether, disconnect and work from laptop only. WWAAAAAIIITT… Now it’s performing as expected!
After some digging I found that neither my CPU was having an identity crisis nor IntelliJ preferred working near the office coffee machine. It’s my 4K monitor. Or, how macOS decides to handle it.
It seems macOS is “optimizing” your scaled display and when you’re running a non-native 4K resolution, it goes bonkers. Somehow macOS seems to do this in software, which (in hindsight, as always) had telltale signs in Chrome (scrolling using the cursor keys) and general Cmd-tabbing through apps. They all get sluggish!
Get out your (nerdy) glasses, because you’re gonna need them, because switching to the native 4K resolution (3840×2160) restores your macs performance!
IntelliJ is on its best behavior, Chrome scrolls as smooth as silk. Life is great again. Yes, the fonts are tiny, but with my 20/10 vision (190% for Europeans) I don’t see a problem (pun intended).
Why this post?
As I said, “After some digging…” so I found the solution, but not with my first suspect/victim, IntelliJ. So let’s see if I can help someone looking for this problem and ending up here, solving her/his problem faster than I did…