Why is Netflix more effecient in Safari than Firefox? I've noticed that when I play Netflix video in Firefox, my Macbook Air's fans spin up to maximum, but under Safari, it stays silent. Why does Safari cause less of a load?
Please see Toms Hardware Benchmark.  This could help explain comparable efficiency between Safari and Firefox.  I have no proof, but a Apple Genius has also told me Firefox is less efficient compared to Safari and Chrome.