Comment 16 for bug 1580792

Did a few tests, dialogs with a black/transparent backgrounds are definitely the worst (Terminal password prompt, shut down dialog, set a code or password in System Settings, connect to a hidden wifi network). The dialog can take up to 20s to fully open. Even then, they remain slow, for example when you type your password to unlock the Terminal (30s from the end of the splash screen to a workable terminal).

Other dialogs also perform very poorly, for example the "new VPN connection" form, or the calendar-app's bottom edge (tested with the snap version) in which you can't really type anything.

The alt-tab switcher is also very (very) laggy and completely unusable. The pointer only move every 1 or 2 seconds which makes it hard to aim correctly at anything. In all those examples, there is some kind of transparency layer involved. Could it be the cause?

As noted in the title, performance is generally slow, so it might also be interesting to see what does work well. For example, tab switching in the browser (bottom-edge style) animates quite nicely once it's opened (though it's a bit slow to open). Moving around in the calendar-app is also quite smooth.

I would have liked to test lists as well, but the address-book-app snap won't work and Dekko isn't in the repos (neither deb nor snap)…

Let me know if there's any kind of test I can do or log I can provide. And let me know if I do have to file another bug!