[2020] DirectX 12 Beta Support: Is Now Live!

11/25/2020 Update

Beta support of DirectX 12 is now live on PC!

We appreciate your patience as we continued to work on this beta support! Please see the OP on how to participate in the DirectX 12 Beta and how to report any issues you come across.

On 2020-11-28 at 8:29 AM, Jarriaga said:

No crashes, but this is a reproducible problem:

 

TYPE: In game
DESCRIPTION: VSync "caps" GPU utilization at 55%, severely limiting performance. DX11 uses as much of my 1070 as it can to hit 60FPS, and then triggers dynamic resolution. DX12 doesn't go beyond 55% GPU utilization and locks me down to 30FPS whenever it can't sustain 60FPS. Dynamic resolution doesn't seem to be triggering.  
 

VISUAL: Format -- GPU / Temp (Celsius)  / Utilization % / Memory usage %

1/3 -- DX11 Vsync ON 3840x2160 (71/98/46)

2/3 -- DX12 Vsync ON 3840x2160 (65/51/39)

3/3 -- DX12 Vsync OFF 3840x2160 (70/99/47)

REPRODUCTION: Enable Vsync when DX12 mode is active at 3840x2160 native full screen (Refresh rate 60Hz). Other settings used: Nvidia control panel VSYNC mode: FAST, triple buffering is ON, Enhanced graphics engine is active, dynamic resolution is active (Auto).
EXPECTED RESULT: DX12 VSYNC should not cap GPU utilization.
OBSERVED RESULT: Severe performance degradation due to GPU utilization cap when DX12 Vsync is enabled. 
REPRODUCTION RATE: 100% reproduction rate. Disabling Vsync in DX12 or switching back to DX11 corrects the issue without further changes; turning it back on with DX12 locks me down to 30FPS unless I move my camera to spot where nothing is seen. Issue is seen with Vsync modes "On" and "Auto".

Dynamic resolution can be a bit uncooperative; often we're victim to the GPU timing returned by the driver which is not always accurate. Somewhere way back in a dev workshop post I talked about this if you're curious. You might try switching to using max-framerate instead of auto-vsync.

Anyway some improvements for both Dx11 and Dx12 drivers are coming in the next hotfix but I can't say if it'll fix it for you. I did a lot of stress tests this morning and it works fine for me (on a 2080 though).