Unreal Engine 4.9.0 & Windows 10 // How do i start up my project using direct x12 ?

Hey Guys.
I hope you’re able to help me.
With the new Update to 4.9.0 UE its possible to use direct x12.
Does somebody know how i set the start up parameters that i’ll use direct x12 and not dx11 ???

Quick Notes:
•UE 4.9 Preview does not yet support Visual Studio 2015. It is expected to be experimental via GitHub for the final 4.9.0 release. For additional information, please view this thread.
•UE 4.9 is expected to run on Windows 10, but has not been thoroughly tested.
•DX12 is still very experimental with 4.9, but it can be enabled by running the editor with the -D3D12 parameter on Win 10.
•UE 4.9 does not support the OS X 10.11 El Capitan beta

You said it yourself: " it can be enabled by running the editor with the -D3D12 parameter on Win 10"

Just create a shortcut on your desktop or somewhere else and edit the link by adding the -D3D12 part.

You can use a cmd window in the directory of binaries/win64 and run the editor with the cmd

Which you can place this into a bat file and use that bat file as the shortcut. Which is what i prefer.


just append -D3D12 at the end of your shortcut properties of the UE4Editor.exe shortcut.

I’m trying to run UE4.9 P2 in DX12 mode on Windows 10, but it just keeps crashing when it’s almost done loading. Any tips? I have a DX12 version of the Elemental demo running beautifully, but the editor keeps crashing =/

As far as I am aware thats just the state of D3D12 in UE4, I have my game running in D3D12 on UE4.9 and I get random crashes in different parts of the D3D12 code (But the editor and game do run), all you can do is wait for the next preview and see if its more stable.

Thanks for your answer, Galaxyman. I was expecting this to be the case (but ofc hoping it wasn’t), but I guess I’ll just have to wait.

Great Guys Thank you veeery much !!!

Is this right???

“F:\Unreal Engine 4 Projekte\Epic Games\4.9\Engine\Binaries\Win64\UE4Editor.exe” -D3D12


One other thing of note? In early release notes of NVIDIA’s DirectX 12 driver? SLI is not supported in Dx12. I dunno if that holds true with 355.60 drivers that just released today… maybe try upgrading to that driver? If that doesn’t work and you do use SLI? Try disabling it before running UE please.

Yes, it’s right.

After doing this is there a way to check while your project is open? I have looked thru the different stat options but have not found any way of checking current running version of direct x.

The output log in UE4. Just look through it and you should see mentions of LogD3D11RHI or LogD3D12RHI (Output log can be show via Windows -> Developer Tools -> Output Log)

Awesome thanks!!! :smiley:

Thanks for info. I was going to try Galaxyman’s builds but I just installed Windows 10 so will just try out DX12 first.

Thanks, I found “Found D3D12 adapter 0: NVIDIA GeForce GTX 660M” so DX12 here I comeeeeee

Have you guys who tested dx12 made a performance comparison between dx11 and dx12?
I’ve just tested dx12 in one of my projects and got a 30fps drop (from 110 to 80).

I get it’s an experimental feature and so but… I’ve recently bought a 980Ti as a “future proof gpu investment” and with all that thing about nvidia cards & dx12 going on, I’m start getting worried…

Any idea what I append the ‘-2015’ argument to for VS2015 support? Right-click project generation’s a no-go.