On: Firefox 92

[pajko]

It could be related to https://www.vsynctester.com/

[pajko → pajko]

Another issue could be https://krpano.com/ios/bugs/ios8-webgl-video-performance/

For me, ungoogled-chromium 89 gives 60 fps, while Firefox 91 gives 14 fps on the same machine (x201-520m, Win7)