Since the update to Firefox 107.0 (now on 107.0.1) from 106.0.5 on two Intel-based Macs with Intel integrated graphics running Windows 7 (I know...) under Boot Camp, I'm … (tuilleadh eolais)
Since the update to Firefox 107.0 (now on 107.0.1) from 106.0.5 on two Intel-based Macs with Intel integrated graphics running Windows 7 (I know...) under Boot Camp, I'm experiencing poor graphics performance in Firefox. I first noticed this when scrolling felt choppy and then subsequently on video playback (YouTube and other sites). Text input and other animations can also feel more laggy or jittery than previously.
This is very similar to what I first experienced when WebRender rolled out to these devices. At the time, I set gfx.webrender.force-disable=true. However, I believe that setting hasn't been heeded for several versions, so I was eventually using WebRender without issue. The release notes for 107 do not suggest that anything related to WebRender or compositing have changed, which makes this particularly baffling.
The amount of stutter is compounded after opening a second Firefox window (regular or Private Browsing).
I have tried Troubleshoot Mode with extensions disabled and disabling hardware acceleration, but the problem occurs in either mode (confirmed with about:support showing "WebRender" or "WebRender (software)" as appropriate).
I enabled gfx.webrender.debug.profiler=true to examine frame rates. Shortly after launching Firefox, frame rates remain around 60 fps and things feel smooth for a bit. However, the frame rate will periodically drop to about 22-31 fps for 5-10 seconds while playing a video or continuous animation without interaction. Viewing Task Manager for all users during this process does not show a notable spike in activity for other processes when the frame rate drops and overall CPU load is nominal.
Opening a second window causes the frame rate for all windows to drop to 30-31 fps maximum, which similarly periodically falls to 12-15 fps for a few seconds. It's clear that the target 60 fps is not maintained when more than one Firefox window is open. I had not checked the reported frame rate with a second window open in prior Firefox versions, so I do not know if this is a change, just that I hadn't observed an apparent degradation in regular use.
The two graphics cards in question for these two machines are:
Intel HD Graphics 3000
Intel Iris Pro Graphics 5200
I believe both are updated with the last OEM (Apple) Boot Camp drivers for this hardware which, granted, are on the old side. I have not yet attempted later drivers directly from Intel, as I hadn't encountered issues until this recent Firefox update. I have not noticed an issue on my other machines running Firefox.
Any suggestions on restoring the graphics performance would be appreciated.