The ouya thread is here: http://forum.xda-developers.com/show....php?t=2294465
I found it by starting to dig into fb0, which is the filesystem device, it's here on our boxes: /sys/class/graphics/fb0
In that directory there are a bunch of 4k state files. But I have a hunch that this just controls what the box outputs, and the video card probably isn't going to be happy with us trying to tell it to output 95% of 1920x1080 or whatever... There are some interesting options though, like "Virtual_size".