User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0 Build ID: 20160502172042 Steps to reproduce: I'm getting ready to publish a WebGL/HTML5 game to Kongregate using their standard WebGL Template. I'm running 46.0.1 on windows 10 64 bit (16 gigs of ram), with a 3570k core i5 and an amd 7870. It's a unity game, compiled under 5.3.4f1 Actual results: Firefox's WebGL performance tanked. It's ~35% lower than Chrome or Edge. And ~35% lower than Firefox running outside the template. I suspect it's because Kongregate uses a scaled canvas in an iframe (which is the only cross-browser way to avoid unwanted scroll bars) I've done my best to replicate the results outside of kongregate. You can find my benchmarking tool at: http://neurowocky.com/tesla8_bench/ Expected results: Chrome, Edge, and Firefox(without the template) average about 55 frames per second on my test machine. Firefox with the template, drops down to 40 fps (and stutters badly).
Thanks for the detailed and useful bug! I tried here but I'm getting a solid 60 FPS on 'Best' but it's a fairly decent mac laptop. It would be really helpful if you could collect a profile for both the iframe and non iframe version on your test machine: https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Reporting_a_Performance_Problem By comparing the performance of both it might hint what slowdown we're hitting so that it can be fixed.
Ahh nevermind on the profiles for now. The symbol server is down and it wont work.
Does this perform any different now with Firefox 47, 48 Beta, 49 Aurora, and 50 Nightly? If the issue still reproduces can you please attach a copy of about:support?