There is definitely a sense of the blind leading the blind on the settings. I was half expecting for someone to yell ‘It turned me into a newt!’ in that forum and people to all agree at one point.
The way to see it is that SteamVR uses a base resolution of the headset they first designed, the HTC Vive. That has a per eye resolution of 1080x1200. That would be 100% in SteamVR Video settings.
The HP Reverb per eye is a 2160x2160 resolution. That’s (taps on calculator) then means 1080x1200 = 1,296,000 total pixels versus 2160x2106 = 4,665,600 total pixels. So 1,296,000 ÷ 4,665,600 = 3.6. Because 3.6 is two squared numbers compared, we can take the square root of 3.6 and we get 1.897 as a ratio.
So 188% (or technically 190%) is the ‘use at native resolution’ Steam SS VR value to use for the HP Reverb.
This assumes:
-
DCS Pixel Density is set to 1.0 (otherwise they combine and multiply the end resolution, leading to a maximum buffer size of 4k by 4k, which is why people see no real benefit over a certain massive number, but still bad frames per second).
-
SteamVR isn’t updated to correctly read the native resolution from the Reverb, and just assuming it is the ‘Vive 1.0’ base instead.
-
Windows 10 1903 pre-warp frame buffer is not maxing out the initially rendered resolution to ‘1.0’ due to a bug in Windows (assuming it also impacts the HP).
-
You’ve turned on (from the default setting of off) of SteamVR ‘Settings / Video / Use custom resolution’ and set a manual resolution, otherwise it will by what SteamVR is good for your system, meaning different people will see different things by default.
I should write a short tech article called ‘VR Myths and Mysteries!’ or something. Other stuff I often read online and can’t reconcile with how the render pipeline works is stuff that contradicts things like:
-
SteamVR Motion Reprojection settings do not work with WMR. They are completely ignored. The only way to set this is via the WMR config file, instructions here.
-
Nvidia or AMD driver settings for MSAA/SMAA/FXAA, VSync etc are all ignored in VR. The only driver settings work using would be power profiles or possibly pre-rendered frame limits, and even then if the game supports that.
-
The WMR Driver for SteamVR just id’s the headset as part of SteamVR, it’s not a layer than translates the buffer or is ‘slower’ or ‘feels wrong’. It really doesn’t take any runtime perf away. It’s just the SteamVR implementation of whatever game you are using with it.
-
What you show on your monitor doesn’t impact your VR performance, as essentially it’s just copying a finished buffer. You can full screen, 4k or do whatever you like, and it’s not running the same pipeline twice, it’s just blitting the end result to a target that is taking VRAM anyway.
Anyway, the internet is about 58% incorrect a lot of the time anyway, so the trick is to ignore it all 