Mozilla Connect

@A1ucardDarn, you're right. I also just noticed that the about:config entry doesn't do anything at all. Very disappointing.

I've just seen, that it is already there, but it's a hidden feature. To turn in on, go to:about:configgfx.webrender.super-resolution.nvidia (true) 

I absolutely need that too, because I have graphics cards from the 40-series and don't want to use any browser other than Firefox. VSR is great and works like a charm on certain occasions.