>>6678652Users with no extensions installed have e10s enabled by default as of Firefox 48, others can change a few about:config prefs to enable it. Many extensions do not support e10s yet, but Mozilla came up with some sort of compatibility layer, which is slower than disabling those extensions, but still faster than without e10s.
browser.tabs.remote.autostart -> true
layers.async-pan-zoom.enabled -> true
extensions.e10sBlockedByAddons -> false
extensions.e10sBlocksEnabling -> false
Restart, go to about:support and check "Multiprocess Windows", should be 1 out of 1.
Also, you can disable the compatibility layer to see which incompatible extensions stop working (uBlock Origin already works with e10s, dunno about uMatrix):
extensions.interposition.enabled -> false extensions.interposition.prefetching -> false
Oh, and I almost forgot: dom.ipc.processCount has to be greater than 1 for it to actually make multiple processes. This value is how many processes the browser is allowed to spawn for your tabs.
