How to properly check fps in VR? (30 fps lock issue)

Sooo, i was trying to find out best settings for different applications while trying different supersampling ranges through steamvr and noticed that my fps in project cars and couple other games is locked on 30 fps.
The question is if the fps shown on my monitor is exactly same as in hmd and how to find if the game performs good or not?


p.s. i run 1080gtx, so there should be no lack of ressources to get more then 30 fps. Screenshot from the top is made with lowest quality (lowest ingame, fullhd pimax / not 2k, no supersampling, no aa; enabling all this things keeps same 30 fps)

Haven’t looked myself yet. Last post mentions steamvr setting on desktop.

The mirror from what others say is only a reference window.

SteamVr, Nvidia (GeForce experience), Fraps, they all only show the FPS on the windows screen, not on the headset. I’ve been trying myself and found no way to see it on the actual headset

It locks at 30 fps if you have reprojection turned on. From what I understand it copies every frame and displays it twice making a smoother vr experience but its what gives the ghosting (I think from what I understand) enabling vr to run on low end pcs
If you turn of reprojection you can get higher frame rate, you need a constant 60 or above for smooth natural experience.
This is on AMD cards nvidia have asynchronous reprojection which is better. AMD are working on this but not out yet.

Play around with the three different settings in steamvr asynchronous reprojection, interleaved and always on while a benchmark is running and you can see the fram rate bar. You will see the effect it has on the frame rate.

I’ve been playing around with it this weekend.

Asset to corsa gives me the best smoothest vr experience I can have that with no reprojection. Project cars is very poor in comparison.

Sj have you checked in steamvr desktop settings? That post i found said there is a buried setting “show in headset” not home so haven’t been able to check.

Ah yes, it’s in the SteamVR settings under Performance and then the button Display Frame Timing, which will open a window and then you can select ‘show in Headset’. But I’m not sure what I’m looking at exactly, I don’t think it’s FPS ? And it just seems to mirror the window to the headset.

Cool was curious. But yeah steam seems to be vague on alot of steamvr things… Ie testvr performance

“Reprojection” must be the issue of locked fps, will try it in the upcoming days :slight_smile:

Steamvr perfomance information is not so easy to understand, there is no clear fps counter.

Well, i’ve tried different settings on project c.a.r.s, as you said - it performance is very poor.
To hit stable 60 fps with my 1080gtx i had to competely disable steamvr supersampling. Most of game settings are on high, downsampling set to DS2X. Setting downsampling higher or enabling steamvr supersampling makes the picture much better, but the fps wont go above 30-45

So now the questions are:

  1. is that reprojection turned on by default for all vr users?
  2. is it necessary to have 60 fps with reprojection turned on (if yes it’s still not clear how to find out if the game runs with 60 while reprojection turned on) or maybe it is designed for 30 fps? In that case we could increase the graphic quality using supersampling. Its actually very important, because im really not sure what is better (for project cars as example) to set supersampling quality higher and play with stable 30 fps or less resolution for better fps.

TO answer

  1. I do not think it is, not 100 per cent on that tho

  2. No a game can run under 60 fps and will be capped at 30 fps (each frame being double up by the software), i think that is what causes the blur when you turn left or right, or at least increases it.

As for what is important, well i guess it is preference, the only game i can get running well without reprojection on is assetto corsa, the choice is everything set low nothing fancy on and it will run at over 60 fps and look great, head tracking seems perfect. less image blur.

But with everything maxed out and reprojection on it looks amazing and is nearly as smooth as without so for now i am going for it with it on.

However it is worth playing around with the tick boxes on or off for each peace of software, it can make a big difference.

from what i have read if you are running a nvidia card then you are safe to use asynchronous reprojecction, It apparantly gives very close to perfect results, does not work with AMD cards.

I have also read of people struggling to max out a game in vr with 2 1080s !

and if you have your pimax in 2k then it is doing even more work !

@industria if you can try it out in Assetto Corssa the vr experience is so much more. The difference in performance between the two in VR really surprised me. Project cars is a lot of fun tho.

I’ve read couple articles from google and found out following:

  1. reprojection enabled by default and turns on automaticaly if the game cant perform well (i guess warthunder could be a good example. It has built in fps counter, so there is no need to disable reprojection to find out how it performs. With the supersamling set to 1.5 i can get stable 60 fps, but as soon i increase this above 1.6 it locks on 30 fps. I think it’s because the game cant perform 60 fps, so it enables the reprojection and lock the fps)
  2. reprojection halfs the refresh rate, basically it was designed for 90hz / 2 = 45hz; 45 fps
    Unfortunately pimax base refresh rate is 60, so all we can expect is 30hz and 30 fps. Thats actually why ghosting in pimax is a bit stronger then with vive.

Good point about all of this:

  • while turned on reprojection allows us to use steamvr supersampling or ingame downsampling on higher setting then other headsets because maintaining 30 fps is much easier then 45 or 60+ (at least for 1080gtx i can make project cars looking really really really good, almost perfect, talking about resolution and vision range)

Bad thing:

  • 30 fps might be not enough for some games, dogfights in warthunder is very ‘laggy’ with 30 fps, while driving a car feels ok.

The info they sell pimax with states the asynchronous refresh rate is 90hz. I wonder if that’s true ?

here is a post i found from the pimax support team, so it should do 45 per eye ! good luck getting a answer from support as if this is the case.

PimaxVRSep '16
@ thebunnyrules
As you know, for VR optical system, the left screen with left eye part is entire isolated with the right screen with right eye. VR optical system is much different with normal view system. in the VR system, your left eye can not see the right screen, and right eye can not see the left screen.

So there is a channce that you can update the data to left screen and right screen alternatively. this is what we call asynchronous mode. in the mode, we can achieve equivalent higher FPS. 90 or even more

here is a link to the original thread

LOL, that’s just marketing BS. There’s only 1 panel (not 1 per eye), so it just updates at 60 hz, all the rest is BS. You can’t paint only one half of the display.

I think what they mean is that the image for the left eye is 1 frame ahead/after the right eye image, so it’s a software trick. Yet it doesn’t make much sense to me, why not always send the latest possible frame instead ? Maybe it works somewhat smoother, BUT it also introduces more latency (you’re working with an ‘old’ frame)

Haha nice point. Yeah marketing bullshit.

I think the point is to take strain of the gpu and CPU so if it copies a frame and sends it, then the GPU and CPU have a chance to work. So lower end machines can run VR . but yes introduces more lag.

Well it may work if properly supported. However it becomes also a matter of how its implemented.

I know from what i read both nvidia & amd are working on better support for asynchronous support.

Now the question becomes how is Pimax implementing it.

120hz TVs 4 example i believe double the frames in the display instead of accepting 120hz signal(at least as i understand it). Where as why a computer monitor with 120hz refresh support cost more.

I would be curious on amd’s freesync (open) being supported.

Ps if mem serves Oculus is using 60hz with Async to 75hz in cv1

AMD are apparently releasing there version of a synch this month. Not sure if it will be computable with pimax, I am hopeful it will make a difference.
Theoretically could a synch be 120 fps, if the pimax stored a frame and displayed it twice ? So 60 fps out of the GPU