System Preferences > Desktop & Dock > Mission Control > Displays have separate Spaces > Off
So why is it not allowing windows to overlap two displays when that setting is on? Because when it's on a) you can swap spaces independently on each screen and b) you can move individual spaces across displays. If you had overlapping windows, swapping Spaces or rearranging them would produce really weird results.
I think a nontrivial part of the problem here is that if you sit down to write out all the requirements, there really isn't a great solution. If you need to A: be able to use multiple spaces conveniently B: be able to drop back to one space as needed (laptop usage scenarios) C: try to remember previous locations of windows and D: generally work like a standard desktop, you've already hit some fundamental issues. I think the people complaining are probably in a situation where they've always got their particular monitor setup, but the exact same code still has to be able to handle all the situations while maintaining the standard desktop layout metaphors... which the observant will note had decades of development before multiple monitors were a serious concern, so there is a lot of promises that were made before that was a thing that have to try to be maintained. Plus you have to remember the window manager must decide where all windows go right now; it has no idea that the second monitor was just a bit slow to come up and will be around in another 2 or 3 seconds, it has no idea that you're just unplugging it to check the connection, etc.
I think there just isn't a solution to this problem. You can move the mess from that part of the carpet to the other part, but someone's going to be annoyed, possibly everyone.
On a tiling window manager I fairly seamlessly can drop multiple monitors in or out, because the paradigm drops a lot of promises the standard desktop makes, so consequently it can more fluidly move into situations that don't make sense for the standard desktop paradigm. But that's not a practical solution for an OS to deploy in 2024.
Hi - toggling that setting requires a re-login to get Spaces to stop interfering with productive work. The windows still really want to jump to a specific display.
It is true. I’ve been doing multi monitor support on a M1/M3 pro for years now. Triple external monitors (2 off a dock and 1 displaylink). The older amd graphics cards took 10-15s to detect external monitors while the apple silicon chips take 1s.
Untrue :D
System Preferences > Desktop & Dock > Mission Control > Displays have separate Spaces > Off
So why is it not allowing windows to overlap two displays when that setting is on? Because when it's on a) you can swap spaces independently on each screen and b) you can move individual spaces across displays. If you had overlapping windows, swapping Spaces or rearranging them would produce really weird results.