OMG... that's exactly what the problem was. I turned that off and performance is 60fps on Firefox once again. Now I need to figure out how to I detect the condi

OMG... that's exactly what the problem was. I turned that off and performance is 60fps on Firefox once again. Now I need to figure out how to I detect the conditions that I need to turn it on/off... it actually works fine on some Firefox Windows installations at least. https://bugzilla.mozilla.org/show_bug.cgi?id=925025 https://bugzilla.mozilla.org/show_bug.cgi?id=925025 Looks like Firefox does the blur in software whereas the other browsers do it in hardware, but apparently you can turn on gfx.webrender.all to make Firefox do it in hardware, not that it seems to work for me... Edit: It's just easier to turn off blur in Firefox always. So I'm doing that. Turns out there is a clever way to detect Firefox from CSS. Thanks so much for the suggestion!