Crossfire, Vsync, and Multiple Monitors - huge DPC spikes.

Discussion in 'Videocards - AMD Radeon Drivers Section' started by Tsume, Jun 23, 2015.

  1. Tsume

    Tsume Member

    Messages:
    20
    Likes Received:
    0
    GPU:
    2x 290x ref cooler
    I have a serious issue with my two 290x cards in crossfire. This appears to be a problem with AMD's drivers, but their support is less than useless so I am going to post this here in the hope that someone can possibly help shed light on the issue and maybe I am missing something.

    Whenever the following conditions are met:
    • Game running in full screen with crossfire on
    • VSync is on in the game options
    • I have my 2nd monitor (TV) connected and powered on
    I get insane DPC spikes (instead of the normal <100 microseconds, it will go up to 16,000 microseconds with "dxgkrnl.sys" as the cause) and audio from anything outside of the game will be stuttering and extremely laggy. Doesn't matter the audio device - I have used the HDMI audio, realtek audio, usb headset audio, even removed other audio devices... no fix.

    This problem was supposedly fixed around 14.4 yet there there are still many people I see with the problem in a google search, and none that I've seen have found a fix that allows me to use Vsync. I have tried all of the following drivers (doing a DDU between driver changes) and the issue persists: 14.1, 14.4, 14.9, 14.11, 14.12, 15.4, 15.4.1, 15.5, and 15.6. I have updated my chipset drivers to the latest from Intel and I am using the latest BIOS on my motherboard. I have used different monitors and different monitor connectors (HDMI -> DP active adapter, DVI, etc). I have even reinstalled Windows.

    Here are my specs:
    Mobo: Asrock Fatal1ty Z87 Killer
    PSU: EVGA SuprNOVA P2 1000W
    Cards: 2x Sapphire R9 290x (ref cooler)
    OS: Windows 8.1 x64
    Monitor 1: I-INC LCD monitor 1200p, connected with HDMI -> DVI adapter
    Monitor 2: LG Plasma TV 1080p, connected directly to HDMI.
     
  2. Espionage724

    Espionage724 Guest

    Run an admin command prompt and run bcdedit. See if you see a "useplatformclock" entry (if it's there, it should be set to "yes").

    If it's there, you'll need to remove it. If it isn't there, you could try adding it.
     
  3. Tsume

    Tsume Member

    Messages:
    20
    Likes Received:
    0
    GPU:
    2x 290x ref cooler
    Espionage724, thanks for the suggestion. I checked on my system and the entry was not there. I tried adding it (also made sure HPET was enabled in my BIOS) and rebooted, but the issue remains the same.

    I have made a video to hopefully help demonstrate the issue. The problem does not happen so long as nothing hardware accelerated touches monitor 2, and it also does not happen if VSYNC is off. But you can see in the video with VSYNC on and my game running in crossfire (even with the game minimized), the second my chrome window goes even a little bit on to monitor 2 the latency goes up insanely. dxgkrnl.sys is labelled as the culprit. If I move it back to monitor 1 the latency goes right back down. Unfortunately for me, this means I have to choose between screen tearing and not being able to watch videos while playing games.

    https://www.youtube.com/watch?v=cj3o1TaCo4Y
     
  4. Tsume

    Tsume Member

    Messages:
    20
    Likes Received:
    0
    GPU:
    2x 290x ref cooler
    I "solved" the problem by enabling my integrated Intel GPU and running my TV off of that. Working flawlessly now... really disappointed in AMD support and AMD drivers though.

    Hopefully anyone having the same issue will be able to use this as a solution if their mobo supports having the iGPU on at the same time as discreet graphics.
     

  5. haz_mat

    haz_mat Guest

    Messages:
    243
    Likes Received:
    1
    GPU:
    1070 FE
    That is probably the best solution with the current architecture anyways. Forcing the GPU to context-switch between the game and video playback all while V-sync'd is kinda asking a lot from the driver haha. If nVidia managed to get that working with low impact on frametimes I would be impressed.

    I've never had good performance trying to do that kind of stuff - chromecast works well though as long as it doesn't need to recode the stream.
     
  6. Ipak

    Ipak Guest

    Messages:
    4
    Likes Received:
    0
    GPU:
    2x290@1050/1500
    Drivers fault with multimonitor setup when they have different resolution. Just for test you can set main monitor resolution to 1080p, and probably it will be fine.

    Had same problem, and I also solve it by connecting 2nd monitor to igpu.
     
  7. Haldi

    Haldi Master Guru

    Messages:
    319
    Likes Received:
    41
    GPU:
    R9-290 CF
    Does this also happen when you have the whole browserwindow on the second Monitor? Or only when it's on two monitors at the same time?


    On another note... Youtube usese HTML5 Web player right? Why do you need hardware acceleration there? isn't that all going fluent via CPU?
     
  8. Tsume

    Tsume Member

    Messages:
    20
    Likes Received:
    0
    GPU:
    2x 290x ref cooler
    It would happen when the entire window is on that monitor as well. Honestly it doesn't even need to be HW accelerated video, just moving a window around while on that monitor will cause the DPC latency to spike. The problem is just most obvious with video. Also remember Chrome uses hardware acceleration by default.

    Ipak: That wouldn't work for me, as my primary monitor (1920x1200) stretches the image with the worst possible quality and there is no option to just have black bars instead when you use 1080p. But you may be on to something with that.
     
  9. Tsume

    Tsume Member

    Messages:
    20
    Likes Received:
    0
    GPU:
    2x 290x ref cooler
    After over 2 years, this issue has finally been fixed by AMD in the Radeon Software Crimson Edition.

    [77703] A crackling noise is heard when running a 3D application in AMD Crossfire™ mode with Vsync enabled

    Don't mean to dig up an old thread, but figured it's worth updating that they did eventually fix it even if it did take them over 2 years to do it.
     
  10. yasamoka

    yasamoka Ancient Guru

    Messages:
    4,875
    Likes Received:
    259
    GPU:
    Zotac RTX 3090
    CrossFire, multi-monitor, and enabling a secondary monitor where the game is not running at that. The niche of the niche of the niche, if that explains why it would have never even been a priority for them.
     

  11. PrMinisterGR

    PrMinisterGR Ancient Guru

    Messages:
    8,125
    Likes Received:
    969
    GPU:
    Inno3D RTX 3090
    On the other hand, these are their best customers, the people that invest heavily in the ecosystem. And having a second monitor showing something else is not that weird, especially if you have multi-gpu.
     

Share This Page