OpenVR (SteamVR) so much faster than OVR (Oculus VR)... WHY? — Oculus
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OpenVR (SteamVR) so much faster than OVR (Oculus VR)... WHY?

Avatar121Avatar121 Posts: 3
NerveGear
edited September 5 in Oculus Rift S and Rift
Recently bought Rift S and tinkering around to get the best performance in VR games. I've come to find out openvr seem to be 30 to 40% faster than OVR. 
So far I've tested Euro Truck Sim 2, Assetto Corsa, Assetto Corsa Competizione, Rfactor 2 and using steamvr instead of native oculus sdk seem to result in faster gameplay.
I have oculus debug tool to show performance and overhead is anywhere from 30 to 40% more in openvr and better framerate.
I have PD override at 0 with no ASW. I made sure to turn on performance mode in the HMD and turn off anti-aliasing.
The overhead is 30 to 40% more in openvr in the same game. My CPU and GPU usage seem to be the same (over 90%) for both SDKs but I get way more FPS in openvr.
What would be causing this discrepancy?
My spec is below

Gigabyte Z390 Gaming
9900k OCed to 5.3 (Liquid Cooled)
2080 TI FE OCed to 2100 (Liquid Cooled)
16Gig 4000 DDR4 

PS. I've tested with default settings and it's the same.

Answers

  • bigmike20vtbigmike20vt Posts: 3,980 Valuable Player
    edited September 5
    Wow.. well that is a 1st ! I find the exact opposite myself.
    Are you totally certain you have not set up supersampling at the driver level or anything 
    Fiat Coupe, gone. 350Z gone. Dirty nappies, no sleep & practical transport incoming. Thank goodness for VR :)
  • Avatar121Avatar121 Posts: 3
    NerveGear
    edited September 5
    Ok I just did a test with ETS 2 and launched with oculus tray tool. I've only changed the argument in startup to reflex each sdk ; -openvr and -oculus. 
    I've triple checked pixel density to be 1.5 on both AND ONLY CHANGED ABOVE ARGUMENT.. but the funny thing is when I display "application render timing", I get below:

    OpenVR
    App Render GPU time : .8ms to 1.2ms
    App Render CPU time : 6.8ms to 7.1ms
    App Que Ahead time: 4.9ms to 5.2ms

    OculusVR
    App Render GPU time : 10.2ms to 10.8ms !!!!!!   IT'S 10 TIMES THE LATENCY!!!
    App Render CPU time : 7.2ms to 7.5ms
    App Que Ahead time : 5.6ms to 6.1ms


    WHY IS IT DOING THIS?!?! 
    IS MY UNIT DEFECTIVE??????


    PS : I get 15300 in VR Orange Room
    https://www.3dmark.com/vrm/39176305
  • rh_galaxyrh_galaxy Posts: 89 Oculus Start Member
    edited September 6
    My guess is that all timing may report up to 11.1 ms without any frames lost, its mostly a matter of which timing includes waiting until the next frame...

    My guess is that the GPU render time on OculusVR is not the full truth, that it includes some waiting.

    OpenVR also uses OculusVR to render.
    You need to look at lost frame count instead.
  • Avatar121Avatar121 Posts: 3
    NerveGear
    edited September 6
    Thank you rh_galaxy for responding...

    I do understand that OVR needs some latency to sync the gpu,cpu and comp but when I look at the measurements, the overhead is near non-existent. It's usually below 20%. When I use the same exact setup (same SS/PD) with openvr, I get 60% or above and this is evident when I enable ASW, as it's invoking it as it consistently drops to 40 fps contrary to openvr, which I know can't use ASW in Oculus, but stays at 80 all the time (with overhead to spear)
    When I turn off ASW in OVR, I get constant judder and stutter as the performance tanks below 80, which openvr doesn't.
    This is verifiable with everything at constant and just switching the argument for the SDKs in games that are switchable. 

    I'm wondering now whether this is some sort an anomaly of newer SDK (or firmware) as evidenced by below link, which confirms my findings.

    https://www.racedepartment.com/threads/gpu-usage-20-40-less-using-openvr-mode-with-rift.141524/

    If you read the post, this issue seem to occur with recent update that happened on March.

    This issue would be easily confirmed (or not), if VR users would switch SDKs with various game that utilize both, but I assume most just stick with one and not test the other as they have no need or they're content thinking they know the limitations of their systems.

    I guess I'm just a "speed freak" as I was always obsessed with squeezing every ounce of performance out of my PC ever since my first 386sx back in the day :)

    Thanks

  • andysonofbobandysonofbob Posts: 226
    Nexus 6
    I'll test!

    I actively play AC and have ETS2 installed. 
    What do I need to do?
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