Hey Peeps,
Important question for Epic. Windows 10 releases at the end of the month with dx12 and are providing free upgrades to win7 or 8 users if you reserve now, With the massive speed improvements expected on current hardware i REALLY hope Epic have a build ready for us to use. Can i have a little feedback from the Epic devs on this.
Cheers
I too am intrigued about the compatibility with Windows 10 and Directx12…
UE4 already works on W10, as for DX12 - there is a version of UE4 that works with DX12, but it’s kinda behind the scene and you could contact Microsoft to get your hands on it(However release is soon so I doubt this scheme is still viable).
I think we get official support pretty early after W10 release 
I wonder how much performance increases we will really get, will a 980ti perform like 50% better? Or only like 5-10?
The performance increase is dependent on your game. CPU overhead get’s decreased, so if you type stat unit in your ue4 console and look at the draw thread, this is the number that get’s decreased by DX12 while the game thread is not affected and GPU very slightly or not too, I guess. So if your are limited by the draw thread, then DX12 might give you a lot better performance, but if you are not, then you won’t really notice it much. Basically, the worse your CPU is the better DX12 performs compared to DX11.
Latest commits to master added dx12 rhi support. I guess 4.9 will come with dx 12 support.