My experience with multiple monitors at different dpis hits nearly every case of failure he points out.
It's a lot more work to configure.
Apps fail to account for it.
Spanning two monitors results in terrible scaling problems.
Apps that do account for it at start up won't account for it during reposition, so they look fine if they open on the right monitor and terrible if moved to the other.
Getting solid workflows for flexible positioning requires hacks like mentioned at the end for xrandr.
Etc...
So sure, you can do it and it sucks.
That's not really the win I think the author seems to think it is.
I'm not even trying to defend X11, I don't have much love for it. I've done some Xlib programming in the past and I've hated it. I've never used Wayland, and I'm mostly on Windows these days.
But, I don't see how one could make a point that X11 is bad because of poor DPI support.
>Spanning two monitors results in terrible scaling problems.
>Apps that do account for it at start up won't account for it during reposition, so they look fine if they open on the right monitor and terrible if moved to the other.
Especially the second point. Applications on Wayland simply get told what scale they should draw on. No need to determine whether they are on the right monitor or the other monitor, yada yada. For those problems, how can you say X11 is not bad, when clearly other protocols have shown the problem is solvable?
xrandr ?
My conclusion from running this and similar mixed DPI setups over many years is that mixed DPI is extremely poorly tested, if at all, by all vendors. KDE Plasma on Wayland finally pretty much gets it right 98% of the time. X11 wasn't a great experience, regardless of what's technically possible.
Windows has so many annoying issues. Apps are often blurry on the low DPI displays. The mouse cursor has no concept of screen DPI, and treats the entire working area as having the same DPI, so you have to hit the "exits" of the high DPI display just right to land on the low DPI ones. Positioning a window across different displays only scales it correctly on one. There's probably more, but I've been 100% Windows free for a couple of years now.
I wonder how OS X handles it. I don't like that OS, but it sounds like the kind of thing Apple would care about getting right.
The cursor thing isn't really to do with DPI, it's a general thing with mixed reported display sizes regardless if they have the same DPI. I wish more systems had the option to cross borders at the relative position between monitors rather than the absolute but neither is necessarily more correct and I'm sure many prefer the absolute method.
Low DPI screens are near unusable anyway on macOS without subpixel rendering
It absolutely is during dragging. macOS is perfectly capable of drawing a window on two screens at the same time, but it doesn't let a window cross two screens while resting which I think is a really good user experience choice.
Apart from automatic OS-level scaling applied as a post-processing step, which is almost guaranteed to look bad, this one is basically impossible to fix (from a technical standpoint). If you need to move "smoothly" between monitors, get identical monitors.
I use FreeBSD as my daily driver and as well I use four screens, 2x4k and 2x1080p.
There are glitches and it's no near perfect but I would highly praise Xorg/X11. I've had no issues in a long time; maybe it's your distro.
[1]: https://lobste.rs/s/ceylzx/forbidden_secrets_ancient_x11_sca...
Aside: I don't know what it is about the Asahi Linux people that they always need to have the most aggressive takes, assuming hostile malicious intent from anyone who doesn't agree with them or doesn't share the same priorities. These people are just absolutely toxic.
Most of the comment is a rant about "X11 proponents". Can we please at least try to keep identity politics out of display servers?
Which fundamental issues does Wayland have with DPI? I'm not aware of there being any fundamental issues with the DPI handling there.
"If you think this idea is a bit stupid, shed a tear for the future of the display servers: this same mechanism is essentially how Wayland compositors —Wayland being the purported future replacement for X— cope with mixed-DPI setups."
now where did I hear that, many years ago..
sad that corporate interests (or wetf) are blocking X11 updates, though I don't trust the quality of Xlibre given the regressions the dev introduced previously
was planning to go back to Sway once I finally get a 4K monitor..
- it will require a lot more memory for cached textures etc. since these are created in a virtualized pixel space - it will look more blurry and wrong, most importantly the text will be less than crisp.
Apart from that, in many situations you have to scale _up_. Try any older random Windows application (that hasn't declared "DpiAwareness"), even older Windows system dialogs, on a HiDpi monitor (say 27" 4K which is about ~163dpi). They get up-scaled by the system and they look _bad_.