Steam FPS VR Question

Just upgraded my PC to a 13900k rog4090OC using most of RYAN’s settings and the VRperf toolkit with a 8KX. Pimax at 1.5/steam 70% for a 4800x4000 normal 150 fov 90FPS

I was doing some testing using the steam FPS VR app to see frame times and CPU/GPU usage to find my bottle necks. I noticed a huge discrepency between what I racing was reporting and what FPS VR was showing.

At 90 FPS I racing was showing 10 on cpu and 7on GPU while FPS VR was 3-5 CPU and 5 GPU. It seemed like Iracing added 2 to the gpu frame times and doubled the CPU frame times compared to FPS VR.

Has anyone else come across this? Any ideas why there is such a big discrepancy especially on the CPU frame times? Which one is more accurate?

If I had to guess I’d say it is VRPerf tool kit FFR upscaling which unloads the GPU while placing some of that load on the CPU but it shouldn’t be double.

Would love somefeed back.