> broken display on "low-res" (1440p/QHD) external displays

Curious as to what's being referred to here. I've used 27" 2560x1440 displays with macOS for a long time, both with Intel and M-series Macs.

IME, 1440p at 27" looks really bad if you're used to 4K at 150% (effectively 1440p).

I had to buy a new monitor and went with a 1440p to save money, but returned it and got the 4K. It's significantly better.

The register link goes into more detail - basically Apple dropped (or never had?) fractional scaling. So for an m2 Mac the external display and internal display will look different (unlike, say with Linux/Wayland - or with an apple hidpi external display).

They most certainly have never had fractional scaling, you get either 1x or 2x.

To be more precise, fractional scaling in macOS is implemented by rendering the entire display at 2x dpi at a resolution greater than the actual display resolution, then scaling the entire output down to the display resolution.

In some ways, this is smart - it avoids the need for applications to handle anything other than 1x and 2x modes, and it avoids the complications of handling fractional pixel sizes (how does an application draw a 1 logical pixel wide line at a 1.5x scale).

In other ways it is monumentally stupid. The macOS technique wastes resources rendering at a higher resolution than you actually need. Worse, even though the downscaling is excellent in macOS, it still has ringing artifacts and it still is blurrier than native fractional scaling.

This is personally one of the things that I hate most about macOS. Many Mac laptops ship with internal displays that default to a resolution that is scaled in this way (though fortunately not the 14/16 inch Apple Silicon MacBook Pro). That's annoying, but it's not nearly as bad as the situation with external displays. I use a UHD (3840x2160) 32" display. On Windows it's perfect at 1.25x scale. On macOS, my laptop ends up rendering at 6144x3456 and then scaling the output down. This looks very noticably blurry, and it's a huge waste of resources.

Only Windows really gets this right among desktop/laptop operating systems.

GNOME uses the same behavior as macOS, except that the "render at higher resolution and scale down" options are hidden by default, and the scaling itself is a lot blurrier.

KDE does support native fractional scaling, but there are a ton of bugs related to rounding errors causing 1px gaps and random cases where applications end up being blurry, especially on Wayland. Worse, display scaling changes often don't apply until you log out or restart applications, which is particularly annoying if you have a different scale factor on an internal and external display.

Windows on the other hand handles this relatively well, although there are still some annoying bugs on Windows 10 related to the taskbar and notifications (mostly fixed in Windows 11). There are also still a lot of Windows applications that do not handle scaling at all, which end up in blur city.

> Worse, display scaling changes often don't apply until you log out or restart applications, which is particularly annoying if you have a different scale factor on an internal and external display.

This doesn't sound right - i had gnome/Wayland running on two external displays with different fractional scaling - and a window spanning the gap or being moved from one screen to the other looked fine?

This (fractional scaling) only worked under Wayland - but there it worked fine.

I used external FHD displays and the result was a blurry mess with obvious fractional scaling applied (nothing was aligned to pixel boundaries)