Firefox Flash hardware acceleration broken in Windows 8 for AMD 4870

[Aretak]

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.

[Guest]

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.

[MrX1980]

Do you have also tried the Flash Player beta ?

http://labs.adobe.com/downloads/flashplayer.html

or

http://www.mozilla.org/en-US/firefox/channel/

[Guest]

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?

[Guest]

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?

[Test Screen Name]

Fixed? You jest, surely. Soon Microsoft will remove Flash from your system, and the problem will not apply. If you have sites that need Flash, they are dead.

[jeromiec83223024 · Accepted solution]

I'm not sure why this thread from 2013 has been revived, but I'm not seeing any additional useful information.  I'm going to lock this thread.

Flash Player has reached it's end of life.  Here's the original announcement from 2017: 

https://theblog.adobe.com/adobe-flash-update/

The current versions of Firefox, Safari and Chrome have all dropped support for browser plug-ins, including Flash.

Here's the consumer FAQ: 

https://www.adobe.com/products/flashplayer/end-of-life.html

Here's the enteprise FAQ: 

https://www.adobe.com/products/flashplayer/enterprise-end-of-life.html