What is interresting is during the beta, with the Index, I often could get better fps making FS2020 stick to 40fps (with 80Hz Index) whereas it would lock to 30fps if I was setting the Index to 90Hz. Since a few SteamVR updates, anything other than 90Hz is causing more cpu/gpu sync problems.
Actually it shows in the SteamVR log files where FS2020 is failing sending the view nearly 10 times per seconds:
What @D4EF1n4tOR is saying is the same as what I’ve documented in “My 4K Settings” and this could be a solid lead. In effect, although my system was for example capable of pushing 55fps in 2D, when I was using FS2020 V-Sync at 30Hz, it was displaying at 27fps (not 30). It is has if the code logic in FS2020 dealing with frame syncing is late enough to miss some frames. And as a matter of fact, the frame timing I’ve captured (link above) are showing a state where FS2020 is late “presenting” the views 10 times a sec (at 90Hz). In other words it is late nearly 10% of the time, and when looking at V-Sync 30 displaying 27fps this is also 10% less…