As you may know, Alyx uses an adaptive/dynamic scaling algorithm depending on your card’s performance headroom – it subsamples in demanding scenes and supersamples in undemanding scenes. You can watch the levels bounce around if you use the command line VR performance HUD at the game’s default settings.
SteamVR changed the naming from Supersampling to Super resolution. And changing the SteamVR settings do nothing.
But be careful with the console commands to force supersampling. Reprojection is more unsettling with Alyx than with many other games. That said, here’s how to do it.
I wasn’t able to use a single command line to set the CVARs. I used this method successfully to benchmark the performance of 13 video cards (as posted by Avery3R – big thank-you to him!)
Launch alyx with -console -vconsole, then press the backtick/tilde(~) key on your keyboard to open the console. Type in vr_fidelity_level_auto 0 and hit enter, then vr_fidelity_level 3 and hit enter again.To test if Super resolution remains at 100%, keep the console open and type vr_perf_hud 1
Of course, you can use level 8 which appears to be a 1.5X supersampling setting; level 0 is no supersampling. But beware that setting level 8 requires a RTX 2080 Ti to stay out of reprojection.
I’ll post a full performance and IQ comparison review tonight after I finish wading through a mountain of data and make all of the frametime and interval plots for each card.