[nowahe]

I've never pushed it enough for it to completely lock up, but I've had some weird bugs/crash happen to me. Like all webviews crashing at the same time (all electron apps + all browsers), with an impossibility to run anything (commands would hang, trying to open apps didn't do anything, etc). But what was uncanny was that the UI would happily run smoothly at 120hz, with all the menus still working and being responsive.

However I've had a lot of issues with WindowServer. I have an external 4k display connected to my mac (Macbook Pro 2021 14"), which I usually scale down to 3200x1800 HiDPI. And 2-3 days after a fresh boot, I'll start to have issues such as the WindowServer process jumping to around 140-180% CPU, and staying there until I reboot (or restart the process). I'll also randomly have my cursor start "glitching" and jump around in a 20px radius around the place I want to point; but only on my external screen.

My feeling is that it has something to do with the non-integer scaling I'm doing , and WindowServer entering at some point a state which introduces rounding errors (which would explain the glitching cursor) or something like that. Also, switching resolutions (or even refresh rate) of the external display will temporarily fix the cursor glitching issue.

But my biggest complain, by far, is that there is virtually zero way for me to troubleshoot/debug the problem. As far as I can tell, there is no way for a debugger to attach itself to the WindowServer process, no documentation on internal workings of the rendering pipeline, virtually no logs, etc. I've been trying to narrow down those issues for 6-8 months, and I've stilled not been able to track it down

[ianai]

Have you tried sticking to the default scale (1:1) for a couple days or other whole integers of scaling?

I’ve seen mine come to a crawl when trying to playback 4k video sometimes. Generally ok with HD.

[nowahe]

I've tried, but for me limiting myself to the default/whole integer scaling is more of a pain than the bugs I encounter with it.

With 4k, at 1:1 I basically have two choices of resolution : either 3840x2160 native (which results in tiny text, even on a 32") or 1920x1080 HiDPI (which is way too small of an effective resolution, especially at 32").

With 1:1.5 scaling, I can get 2560x1440p HiDPI, which seems to be more stable (and renders text more crisply), but still a tad too small for what I need.

A 5k display would fix those issues, but the price difference between 4k & 5k is way too steep to me for the marginal improvement I would get out of it.

However, I've never had an issue with 4k video playback, even on non integer scaled resolutions. What's more, they virtually never drop frames, even with the system under load. My bet is that their hardware video decoding pipeline is significantly better that what's present on Intel CPUs, and is able to better delegate video decoding to the hardware decoders.

[ianai]

But did the issue persist at the 1:1 scaling?