Exactly this.
I just did two further tests:
1. Activated "upscaling" in PiTool for the 8K-X, increased PiTool-resolution to 1.25 and tried playing a bit - but even if FPS increased significantly, I had to abort after a couple of minutes since everything just got so damn blurry I simply refused to play like this
2. Re-activated "native"; then decreased PiTool-resolution to 0.75 and increased SteamVR-SS to 130% which gave me 3860 x 3376 and the following results:
Routes: Boise > Yakima; Yakima > SpokaneGPU: NVIDIA GeForce RTX 3080 (30.0.15.1179, Tavg 64.5, Tmax 69) CPU: AMD Ryzen 5 5600X 6-Core Processor (Tavg 54.4, Tmax 58)
Delivered fps: 67.82 Duration: 70.6min. Headset was active: 100%
GPU Frametimes:
Median: 13 ms
frametime <13.3ms(vsync): 58.9%
CPU frametime:
Median: 11.6 ms
frametime <13.3ms(vsync): 70.6%
Max. SteamVR SS: 130%
Render resolution per eye: 3860x3376(by SteamVR settings, Max.) (HMD driver recommended: 3386x2962)
=> FPS still drop in cities to an avg. of 50 (so ~ +10 compared to before I'd estimate), but go up to 60+ as soon as leaving settlements and most of the time even 70-75!
Of course, the image gets a bit blurry, here too, but... okay... not as much as the first "PiTool upscaling" trial, and it might be a quite good compromise considering the much higher FPS (~ +17 in avg. !!) which make the whole driving feeling much smoother, even and especially in curves.
Just leaves the question open whether CPU frametimes now would benefit even more of the 5800X 3D...
I am a bit undecisive if I should give this a trial, too... especially as I've already claimed it for refund and should return it by Friday latest. I don't really think it would provide me stable 75 FPS in every situation, even with this setting now.
Yes, I absolutely agree with you: Both truck sim's are among my personal Top 5 of the best games I've every played - and I am playing games on PC for more than 30 years now
And yes as well: Next Gen graphics card will be mine, too. I am already thinking about whether to give the new AMD 6950 XT a trial if I can get one cheap enough... Question here, too, is: How much performance gain will next gen GPU's provide over 3080/6950 XT, and at which price?