I'm using a 290X, but the only significant architectural difference is the internal "Crossfire" so I'm fairly sure our Catalyst-Win10-E
-Oculus compatibility situations are the same. I had the same experience after upgrading to Windows 10; I'd been using a ~1.5x supersample by using regedit to force ED to recognize the resolution options, with the in-game SS left at 1x and the Oculus Image Quality slider somewhere below half.
After I upgraded Windows I also couldn't get that method to work (it wasn't all that easy to get the Rift and Elite to work at all...), so I decided to play around with the in-game SS and Oculus Quality settings. I'm glad now that it DIDN'T work the same, because it turned out I was able to maintain a stable frame rate with 1.5x supersampling (in-game setting), 2x MSAA (in-game setting, not thru CCC) and the Oculus slider up all the way, even with all other graphics options nearly maxxed. And that looks 10 times better than it ever did with the previous (regedit) method. You'll probably be able to go even farther, possibly to 2x SS and/or 4x AA. I have my 290X running at a 5% overclock, but your card should be able to use these settings without overclocking.
Hope this helps! You'll need to play around I'm sure, but IMO start by setting Oculus Quality all the way to the right, because the difference it makes is HUGE.
After I upgraded Windows I also couldn't get that method to work (it wasn't all that easy to get the Rift and Elite to work at all...), so I decided to play around with the in-game SS and Oculus Quality settings. I'm glad now that it DIDN'T work the same, because it turned out I was able to maintain a stable frame rate with 1.5x supersampling (in-game setting), 2x MSAA (in-game setting, not thru CCC) and the Oculus slider up all the way, even with all other graphics options nearly maxxed. And that looks 10 times better than it ever did with the previous (regedit) method. You'll probably be able to go even farther, possibly to 2x SS and/or 4x AA. I have my 290X running at a 5% overclock, but your card should be able to use these settings without overclocking.
Hope this helps! You'll need to play around I'm sure, but IMO start by setting Oculus Quality all the way to the right, because the difference it makes is HUGE.