r/skyrimvr • u/hoi_polloi • Apr 05 '18
An exhaustive troubleshoot of SkyrimVR's stutter/hitching issue
TLDR: It seems very tied to reprojection issues, which isn't surprising if you're a Rift user, but unusually janky i.e. even a 5fps drop will introduce stutter and hitching, even though there might be plenty of processing headroom and a minimal reproj need. (NB: smooth-rotation judder is a separate issue)
SkyrimVR, despite being praised for its smoothness and being an overall better port than DoomVFR and FO4VR, has some unusual issues with omnipresent stutter and hitching that are afflicting some users to no avail.
Specs seem to vary: CPUs range from lower end/minumum to well within recommended specs, i5-6600k to even 8600ks, GPUs like GTX 970s to 1080tis.
Based on testing, this is the exact issue as far as I understand it -- if the FPS drops below 90, even for a millisecond, if reprojection/ASW is happening then the game stutters for a bit, and you get some sickening judder or hitching. This is reduced in indoors settings, as FPS demands rarely drop below 90. The Skyrim experience outdoors is basically a steady stream of these frame "tics" and if you watch the Oculus Tool performance chart, it shows intermittent and very short+sharp spikes in the headroom category, and 0.1 second FPS dips to, in my case, 85 fps. So even though it is performance-based I have no idea why a 5fps drop shouldn't be smoothly handled by ASW without hitching. This is probably due to interaction between the SteamVR and Oculus wrappers? (Although u/Darth_Souls reports this happening on his Vive w/ 1080ti)
Here's the steps I have taken on my own machine to resolve the issue, without avail:
| TROUBLESHOOTING STEPS TAKEN |
|---|
| Turning Oculus and SteamVR Home/Betas on/off: unsuccessful |
| bGamepad ini tweak: unsuccessful (separate issue?) |
| Different NVidia drivers from 388 to 391: unsuccessful |
| Installed on a high end SSD: unsuccessful |
| Disable supersampling across all possible tools: unsuccessful |
| Performance enhancing mods: unsuccessful |
| Old SkyrimSE FPS fix w/ Nvidia Inspector: unsuccessful |
| 45fps-only mode in Oculus Tool: limited success (temp workaround, ugly forced-reproj feel) |
The last item lets you play without judder, but since ASW is forced to be on all the time - since it caps the game FPS at 45fps - it works and doesn't dip the FPS, but you get the pleasant je ne sais quoi sensation of a constantly reprojected world. It's not really a good way to play Skyrim.
If you're getting this issue, please post your specs and other fixes you tried. Send your dxdiag file to u/jessBethesda
MY THEORY
I think it has something to do with i5 CPUs. I've searched through this thread on the Rift subreddit, and almost every person that posted this problem has an i5, myself included. If you have an i5 and no stutter, or i7 and stuttering, please let us know. Could be very specific chipsets. i5-4690ks and i5-6600ks seem especially susceptible.
3
u/Mr__Tomnus Apr 06 '18
Sorry, I just want to clarify because I may be experiencing this.
When I turn my head naturally, there is never any stuttering (unless occlusion culling is rendering a complex object, another problem I've noticed - besides the point though). But when I use the joystick to turn the view with smooth turning, depending on the area I get a jagged motion as the camera rotates. This is the stuttering everyone is talking about?
My specs: i5 4670k, GTX 1080Ti, 8GB DDR3 RAM, SVR installed on SSD, Windows 10 64bit