Abram,
I've tried to adjust the GPU scaling option and it works when the desktops are in extended mode but not when I create a desktop group (eyefinity). My taller screen which is in the middle streches to fit the whole screen.
Is their an option in the monitor OSD? As Abram said.
On my "old" 20WGX2 it is called "Expansion Mode" and if I recall correctly, with this monitor I have, you can select 1:1 (no scaling), Scale to fit aspect ratio, so it maximised the horizonal/ verticle keeping aspect ratio, or fill, to fill the whole screen. Try looking there.