Ps Beta Home screen shows white
Found this looking to see if there was an existing post about UI performance.
As of today’s build ( 27.9 m.3598 July 13th) I’m still seeing what I’d call a FOUC in web development terms, a Flash of Unstyled Content.
It makes the whole experience nasty, not to mention lots of the dialogs when they DO load look scruffy, with alignment and padding all over the shop (Though that’s a different issue to raw performance)

Win 11 AMD 7950 with 64Gb RAM
The file>open dialog, for example. Still trying to work out how to disable the intermediate dialog, but it’s a good example of a first point of contact between the application and the user, and it’s janky as hell :(
