Before this SU10 update I was almost always GPU limited according to the developer both in VR and 2D (2K). Then after the SU10 update and latest NVIDIA driver I tried DLSS in VR. Then fps dropped from 30 to single digit values with the default performance setting. I changed that to highest performance setting and fps got back but things were not better. And now I am almost always main thread limited. Then I switched back to TAA. Then after that I am still reported as main thread limited. And when exit VR I get more GPU limited. Really strange I think. What is DLSS and what is its benefits ?

My system
CPU 4770K @ 4.5 GHz RAM 16 Gb 2200 MHz GPU 2070 Super Win10 and MSFS on SSD VR set HP Reverb G2 and I set render scale to 50 in VR

If you were GPU limited before, switching to DLSS would only make things worse..

As I understand it, DLSS is supposed to render alternate frames entirely on the GPU, thus offloading the CPU.

This would only make sense if you had spare GPU capacity to start with..

I was gpu limited in SU9 both vr and 2D. After SU10 I find DLSS much higher frame rates than TAA in VR. I'm still gpu limited.

I cannot run re projection in VR (frame rates tank). I cannot run TAA in VR (frame rates tank but as badly). Reprojection is  turned on/off in Windows Mixed Reality Portal (3dot) settings. And/or in OpenXR toolkit (as opposed to OpenXR Tools which is a different app altogether).

Tp run OpenXR Toolkit, I reprogrammed the hotkeys from Control F2 etc. to the 4 arrow keys for up down right left (menu directions). Because the menu is seen in the headset not on the monitor, so you can't  see the keyboard to type the hotkeys). OXR Toolkit settings make the biggest difference in quality graphics and fps. For instance you can change the central sweetspot in the G2 or any headset to large or tiny. Large looks better because more of the whole view is in sharp focus, but there's an fps penalty. You can change all 3 color saturations red.blue,green and zillion other settings.

My system  is less but I get the same differences in SU10 between DLSS and TAA as this guy.

 

But at first I was getting fps = 8 :(.... changing the settings I now get 45 fps and am using DLSS Quality, 100 both LODS, reprojection off (also off in MSFS settings). DX 11.

So i'm not surprised the OP was getting single digit fps, so was I at first (using TAA, DX12, and reprojection ON)