just tried the internal gnome3 feature to support fractional scaling amounts on hidpi displays. it is a mess, it just renders the screen at a lower resolution and then stretches the framebuffer to your screen. embarrassingly bad and disappointing.

background: currently gnome supports hidpi displays, but only in even scaling amounts, ie 100% or 200%, nothing in between. this is pretty suboptimal for most desktop displays, and Linux really needs a way to specify this in more reasonable increments (125%, 150%, 175% being standard on other platforms).