Bad VR performance is back... :(

[Jeo Nugu]

Anyone else who is playing this in VR, please lend me your tales of experience (positive or negative) because my woes of bad VR performance in this game have come back to haunt me!

I know the devs don't want to hear me say "It must be the game's fault because all my other VR games work perfect!", but after many hours of testing the last few days, it's starting to look that way. The main issue is reprojection/motion smoothing and a nasty amount of stuttering or "judder" as some call it. I realize it could be that a recent update to either SteamVR or Windows Mixed Reality is to blame, but I've not really found any combination of settings that solves the issue, although some work better than others.

I also updated my nVidia driver again recently, so that could be part of the problem too, I dunno.

I've tried reprojection disabled, enabled, and forced half-rate. The forced half-rate option seems to have the best results, where the stuttering is mostly limited to train yards, where there are buildings and rail cars sitting around. Outside of train yards, it's pretty smooth and the stutter is only intermittent. Just for the record, the stutter I'm referring to is that effect where everything that is passing by your view has a flickering "double-vision" appearance.

If I set reprojection for disabled, then the stuttering is 100% constant, doesn't matter if I'm in a train yard or out in the middle of a field. It's awful. :(

If I set it for enabled, then it's a mixture, with some periods of smoothness, but I still see stutter more often than not. Oddly enough, it happens inside the cab of locomotives most often. For example, I can drive a locomotive through an area, and I see a lot of stuttering, but if I go back and *walk* through that same area, it's much smoother, showing little or no stuttering. The heck?

I've tried every combination of versions of both SteamVR and WMR... both on beta, one on beta, then the other, WMR on the "LKG" (last known good) release, etc. Generally, there's not much change between them, but the one combo that I've had better luck with is WMR on the LKG release, and SteamVR opted out of all betas. (The current beta branch of SteamVR seems to break reprojection entirely, regardless of settings.)

The weird thing is, if I turn on the frame graph that shows the frame timings, I'm getting at least 90 fps, and often a lot more. So, I can see that it *should* be nice and smooth, even in train yards, but the stuttering is getting in the way, and you can see a series of single-frame spikes on the frame timings, almost perfectly spaced out, where the fps drops below 90.

Kind of like this... (the dots are 90 fps, or 11.0ms, the vertical bars are the spikes)

.....|.....|.....|....|......|.....|.....|.....|.....|....|.....|.....|....

If I turn on the reprojection indicator in the HMD, and enable reprojection, even when I'm standing still in the game, just looking straight ahead, I can see the indicators flip back and forth, between green (reprojection off) and the two blue indicators (reprojection on)... back and forth, back and forth.... every second, like a heartbeat. I've used that indicator in nearly all of my VR games, and I've never seen it behave like that before now. So bizarre.

Yesterday, I pulled a 35 car consist (a personal best) with a pair of DE6's, and once again, I visited the notorious Harbor & Town, and as I drove through the yard, the stuttering was bad enough that I literally had to look down at the floor of the cab for the last bit of the drive, so I wouldn't get a headache from the "double-vision world" outside.

The kicker is that it hasn't always been this way. A couple weeks ago, I posted about having some VR performance issues, but I did a clean install of a new nVidia driver and everything seemed to work well again. But then this stuttering issue suddenly began the day BEFORE the latest game update. I know, right? It would make more sense if I could say, "Oh, this happened when I updated the game to version 88", like a light switch got flipped somewhere, but this problem began the day before, maybe even two days before, so it's not related to that.

As I said, I am reluctant to point the finger at Derail Valley, but I've tested out other games, like HL: Alyx, American Truck Simulator, Project CARS 2, and even the new Star Wars Squadrons, and I'm not seeing any reprojection or stuttering issues in those games. (Well, maybe briefly here and there depending on the scene, but it's uncommon, and definitely not nearly constant like it is in DV.)

This also isn't something that I just tried out for 20 or 30 minutes and made a final judgement call... no, I've been in and out of the game over many hours, testing, changing VR settings, testing again, reading forum posts, looking up tips and tricks, and testing some more. Not only with Derail Valley, but other VR games, including ones that used to give me reprojection problems before I upgraded my CPU. (American Truck Simulator used to be really bad with the reprojection thing, but it runs great now.)

Anyway... Sorry for being so long-winded here, but I just wanted to be sure to give a thorough account of things.

My specs:
Core i7-10700K
RTX 2080 (latest nVidia driver)
32GB RAM
Odyssey+ HMD
(no manual overclocking is being done on any components)

[Sasha]

I'm not really certain what, if anything, could be the issue then. I'll ask around the team and see if there's any further ideas, or if we can look into performance. I really, really hate to say "It works on my machine", but it works on my machine, with a 1080ti instead of a 20XX card, and runs well.

[bgr]

Thanks for the detailed post, there are definitely things in the game that could be optimized better, but for this kind of "on and off" behavior you're describing one thing comes to mind.

It's important that the game window is in focus for best performance, it's enough to click on SteamVR window or desktop accidentally and game will have degraded performance. And this is exactly the thing that's most likely to happen when you're measuring performance - speaking from experience since we were bit by that in the past :)

Apart from that, another factor can be multi-monitor setup (especially with monitors with different refresh rates), so if you have multiple monitors, try switching to only one temporarily.

Also check if Windows' built-in Game DVR feature didn't get re-enabled by a recent Windows update.

[Jeo Nugu]

Originally posted by bgr:

Thanks for the detailed post, there are definitely things in the game that could be optimized better, but for this kind of "on and off" behavior you're describing one thing comes to mind.

It's important that the game window is in focus for best performance, it's enough to click on SteamVR window or desktop accidentally and game will have degraded performance. And this is exactly the thing that's most likely to happen when you're measuring performance - speaking from experience since we were bit by that in the past :)

Apart from that, another factor can be multi-monitor setup (especially with monitors with different refresh rates), so if you have multiple monitors, try switching to only one temporarily.

Also check if Windows' built-in Game DVR feature didn't get re-enabled by a recent Windows update.

Thanks for the feedback, bgr (and to Ivan as well). :)

I have been paying some attention to putting the game window in focus while playing because I know of a few other VR games also work better when focused, so I consider it to be a sort of "rule" for VR gaming. Nevertheless, I will try to be more aware of this as I continue to play and troubleshoot.

I already have the Game Bar (and DVR) turned off since that was a widely recommended trick to get better fps in Micrsosoft Flight Simulator. :P

I only have one monitor, so that's at least one thing we can exclude.

I did read some Reddit posts where people were having the same issue (in other VR games) and several of them reported success with rolling back to an older version of nVidia driver, but it was like version 436.xx, which is a little further back than I want to go. Although I don't want to use too old of a driver on a continual basis because other games I play might suffer, but I may revert back two or three versions just to see if there's a change in the motion smoothing/reprojection in DV. Perhaps that will reveal a clue.

@Ivan - That's good to know that it runs just fine on your 1080Ti, and it confirms my suspicions that my hardware is more than up to the task of running this game perfectly. As I mentioned in my original post, there are areas in the game where I get nice smooth frame rates, and when that is going on, it looks fantastic. :) I just need to figure out why the reprojection wants to keep interfering with that.

Thanks again guys for your hard work and for working closely with the community! I will play some more tonight and test a few things and let you know what I find. :)

[Altfuture]

One more thing that comes to mind. If you haven't already, try disabling Realtime Reflections in settings. That setting can cause spikes as you've described them, but only when the player is moving and only on lower-end hardware. Based on your description it's highly unlikely that this is causing it, but it's worth the shot.

[RWag64]

I'm in WMR VR with an HP VR 1000.

Everything works smooth, except when I approach the Harbour. Here, I always have some stutter for 10 to 15 seconds (when creating the Harbour zone and trains).

[agrimes]

I was pulling 80+ cars through steel mill last night and everything went slideshow. VR seems to have two levels of FPS, game FPS and motion tracking FPS that is locked at 90 hz or whatever you configure. But yeah, the game was lagged to death on that haul...

[Jeo Nugu]

Thanks for the input guys! I'm testing out a couple older driver versions, one of which seems to make an improvement, but I need to play some more to be sure.

@agrimes - 80+ cars?! Holy crap, man, that's crazy! lol

[Jeo Nugu]

Well... after testing with a couple older nVidia drivers I was unable to really find anything significant that might help. Version 441.66 was the oldest driver I could obtain from nVidia's download page and that version actually did seem to have less stuttering than the latest version when in train yards, including Harbor Town, but it was only a marginal improvement. It still had the "on/off" behavior seen in the reprojection indicator that I noted previously.

(I did try version 417.xx, but it crashed my computer before it finished installing, probably because it was released before the 20xx series, and most likely isn't compatible with the Turing chip.)

So, for now, I've gone back to the latest driver and I run with the motion smoothing forced on at half-rate, which gives the best overall results. I can say with a reasonable amount of certainty that longer consists of cars does make a difference in performance, and Harbor & Town is definitely the worst area for stuttering. But, sometimes it's very prevalent in places like Steel Mill and Oil Well Central as well.

It's playable, although not always enjoyable, but I'm kind of just giving in to the fact that this is just how it's going to be for right now. I know my hardware should be more than capable of running this game at 90 fps without using any motion smoothing, but it just won't, and I'll be damned if I know why.

Maybe the next nVidia driver update will make a difference, or maybe SteamVR and/or WMR will get an update that will do something. Or maybe you guys will implement some optimizations in a future game patch. (Fingers crossed on all counts.)

Thanks for all the feedback on this post, I appreciate it! :)

[Altfuture]

You're welcome, keep us posted if it changes!

[craigalexp]

Derail valley has always had stutter issues. I've played it since early access. I'm on oculus. The major overhaul has made the game run better and i have made component upgrades that have helped. micro stutters are still there and still happens when i play in pancake mode instead. I'm also using an RTX 2080. every other game such as battlefield 5 and dirt rally 2.0 in VR run really smooth.

[ElSpannio]

This is the main reason i stopped playing no matter how much i pissed around with settings I just got a ♥♥♥♥ ton of stutter when i looked out to the side. If i looked straight ahead it was nice and smooth but the moment i try to look at the scenery as it went past it was just juddering along so i just gave up trying to get it to be smooth and moved on.

[Jeo Nugu]

Thanks for the feedback, guys!

[craigalexp]

I lock my oculus to 45fps now and its improved greatly. I just want to make it clear the little stutter now is just when i look to the sides at the scenery while the train is moving as someone has suggested. Doesn't put me off the game and still very enjoyable nonetheless.

[Jeo Nugu]

Originally posted by craigalexp:

I lock my oculus to 45fps now and its improved greatly. I just want to make it clear the little stutter now is just when i look to the sides at the scenery while the train is moving as someone has suggested. Doesn't put me off the game and still very enjoyable nonetheless.

Yeah, that's how I have my Odyssey+ set up, locked at 45 fps. It's not perfect, but it has less stuttering overall compared to any other setting.

[Jeo Nugu]

Just a quick update, I played a little bit last night with the latest nVidia driver (v457.51) and it seemed to help a bit. There still some stuttering while going down the tracks between towns, but in the train yards at Steel Mill and Machine Factory & Town, there was noticeably less stutter than usual.