5 ms·page rendering, js performance, ram usage.by kmlx 7y agopage rendering, js performance, ram usage.h2onock 7y agoIs your machine very old by any chance? Although, that said, I have no problems on a 2013 MBP.acheron 7y agoI still use a 2012 MB Air as my home laptop. I've used Firefox on it forever and have never had a problem.