Skip navigation
Currently Being Moderated

Firefox Flash hardware acceleration broken in Windows 8 for AMD 4870

Jun 23, 2013 10:24 PM

Tags: #problem #flash #windows #firefox

I've been having performance issues with Flash in Firefox on Windows 8 ever since I installed it, so I decided to try and get to the bottom of the issue, since Chrome's Pepper Flash plugin works flawlessly on the same machine. I decided to install Windows 7 as a dual-boot environment to do some testing, and installed the same version of Firefox (21), with all the same extensions, the same version of Flash (11.7) and the same display driver (Catalyst 13.1 Legacy). I was surprised to find that the performance issues I'd been having in Windows 8 were completely gone.


On closer inspection, that seems to be because the 'Use hardware acceleraton' checkbox is doing nothing in Windows 8. Whether it's checked or not, playing a beefy Flash video (one of Giant Bomb's HD progressive streams) uses 35-40% CPU and is pretty choppy. The exact same video, delivered via the exact same software but under Windows 7 is entirely smooth and CPU usage is around 5-10% with the checkbox ticked, and comparable to Windows 8 with hardware acceleration turned off.


In another test, I compared videos on Youtube with the information box turned on. In Windows 7 it's showing as software video rendering and accelerated video decoding regularly, changing to accelerated for both in full screen. With the exact same setup on Windows 8, it shows software rendering and decoding no matter what, with the associated higher CPU use and poorer video performance. Incidentally, reverting to Flash 10.3 on Windows 8 completely fixes the problem. Hardware acceleration works as it should in all scenarios. It seems to just be the 11 series that's affected.

Is this a known issue at all, and is there any sort of fix planned? Or is there a way to fix it now? Any help would be appreciated.

  • Currently Being Moderated
    Jun 28, 2013 7:06 AM   in reply to Aretak

    Seeing the same thing with Windows 8.1 Preview. Embedded videos are choppy.


    Win 8.1 x64

    ATI FirePro V4900

    8GB RAM

    Same issue in IE10 and another Chromium browser.


    This is a fresh install of Windows, not an upgrade. Worked fine in Win7 SP1 for months.

    Mark as:
  • Currently Being Moderated
    Jun 28, 2013 10:38 PM   in reply to Aretak
    Mark as:
  • Currently Being Moderated
    Jul 11, 2013 3:22 AM   in reply to Aretak

    I have the exact same issue on Windows 8x64, but have an nVidia GPU.


    I also reverted back to Flash version 10.3, where HD videos work perfectly.


    The issue still exists on flash version 11.8.800.94 in Firefox.


    For me it is only in Firefox that the issues exists, IE plays ok for me.


    Anyone know when this will be fixed?

    Mark as:
  • Currently Being Moderated
    Aug 15, 2013 11:39 AM   in reply to thegilpins

    I have recently tried the new 11.8.800.146 beta and this still does not work properly.


    When can we expect a version 11 solution for WIndows 8 with working hardware acceleration?

    Mark as:
  • Currently Being Moderated
    Nov 11, 2013 9:34 PM   in reply to Aretak

    it seems that the problem might not be from adobe side after all!


    Windows 8 user,

    open firefox and type   about:config      in the address bar and hit enter. Type  “webgl”  into the Filter box and then double click on the webgl.force-enabled option to change its value from false to true.

    Problem solve...Radeon HD-7310 dont know for Nvidia but i assume it will work to.

    Mark as:

More Like This

  • Retrieving data ...

Bookmarked By (0)

Answers + Points = Status

  • 10 points awarded for Correct Answers
  • 5 points awarded for Helpful Answers
  • 10,000+ points
  • 1,001-10,000 points
  • 501-1,000 points
  • 5-500 points