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Up and Coming
October 25, 2014

Half frame rate (37.5) on Linux using SDK 0.4.3

My game starts up normally at 75fps, then after 36 seconds, it suddenly drops to 37.5fps. If I run with vsync off, it runs at ~200fps.

I have no idea what could be causing this. It's always at the exact same time, and it doesn't matter what part of the world is being drawn. Is anyone else seeing this?

    9 replies

    jspenguinAuthor
    Up and Coming
    October 25, 2014
    After some more investigation, I've determined that not setting ovrDistortionCap_Overdrive seems to fix the problem, but I still don't know why.

    EDIT: Here is a minimal demo that demonstrates the problem: https://www.jspenguin.org/software/glbumper/files/simplevr-0.1.tar.gz

    All it does each frame is call ovrHmd_BeginFrame, ovrHmd_GetEyePoses, and ovrHmd_EndFrame.
    New Participant
    October 25, 2014
    I also have this problem with OculusWorldDemo, haven't found out what's causing it yet.

    Arch Linux, kernel 3.17.1, nvidia 343.22 (Quadro 1000m)
    New Participant
    October 25, 2014
    Just FYI I know several people on Windows using SDK 0.4.3 & running Elite Dangerous in Direct mode who are stuck on half frame rate (37.5 fps exactly). One of those is me, in extended mode I hit a rock solid 75 fps.
    Participant
    October 28, 2014
    I'm seeing unusual frame rate drops too, though it doesn't seem to be as methodic as yours. I don't have time to investigate it today, but just got the DK2 integrated into our engine and this is causing trouble.

    I'm on Linux using seperate X screens.
    Participant
    October 29, 2014
    "MarkDon" wrote:
    Just FYI I know several people on Windows using SDK 0.4.3 & running Elite Dangerous in Direct mode who are stuck on half frame rate (37.5 fps exactly). One of those is me, in extended mode I hit a rock solid 75 fps.

    I have this exact problem in Direct to Rift mode, unfortantly my DK2 is not detected in extended mode.
    New Participant
    November 1, 2014
    I have the same issue.

    Running Windows 8.1, GTX770/i5 4790k

    wtf?

    EDIT: This in E:D, too
    Up and Coming
    November 4, 2014
    I've found that this isn't so much a lack of framerate, but a lag in head tracking. I get a constant lag in every demo on Linux (including the Desk and Tuscany demos), while under Windows there is no such lag. One thing I noticed in Tuscany, however, was that if I kept my head still and moved, the lag was not evident. So something tells me it's a problem with oculusd itself in relation to recieving these values in the applications. Perhaps someone could make a test application (a terminal app or something) to see if there's just a large amount of latency updating those values?
    Participant
    December 14, 2014
    I've got the same problem on Linux with SDK 0.4.4
    fps is stays around 30 even if I run demo without oculus turned on.
    New Participant
    December 14, 2014
    The first time I ran your simplevr demo under Linux, the console output reported around 30fps from the very beginning. The second time, and all subsequent times, it reported ~60fps (not 75) long past 36 seconds (I ran it for up to 2 minutes). I do get judder, as I do with OculusWorldDemo from both 0.4.3 and 0.4.4 (I do not get judder with games compiled with 0.3.x). I had oculusd from 0.4.4 running.
    Gentoo Linux 3.14/DK2/i5-4670/GTX660