为了改善 Firefox 的性能，Firefox 在开发版里开启了一个名为 Electrolysis 的特性，这个特性的一个重要的元素就是支持多进程（multi-process content processes），虽然官方说，这个功能正式启用至少要到 Firefox 48，现在的 Firefox 主流正式版本还是 47，不过你可以强行开启，而且不需要你安装 Nightly 版本。
首先还是进入 about:config 页面进行设置：
Firefox 48 for Windows, Mac and Linux has been officially released and available for download. Mozilla has planned to ship Multiprocess Windows (e10s) to one percent of eligible users who have no extensions installed, to check your Mozilla browser after installing Firefox 48 has e10s enabled or not and know how to enable it if Multiprocess Windows was disabled for you.
READ: e10s in Firefox 48 release: Eligibility Criteria & Release Plan
Visit about:support, if e10s turned on for you, you’ll see ‘ 1/1 (Enabled by default), under Multiprocess Windows line item,, if not you’ll see ‘0/1 (Disabled)‘, this will be the case for most of the users.
Multiprocess Wndows disabled
If e10s is disabled for your Firefox, don’t worry! you can still enable it manually,
Manually enabling e10s in Firefox 48 if disabled by default
1. Visit about:config and set browser.tabs.remote.autostart preference value to true. If it was already set to true, no need to make any changes.
2. Now create a new boolean preference named ‘browser.tabs.remote.force-enable’ and set its value to true. if you’ve any accessibility tools installed, change accessibility.force_disabled preference value to false 1 from 0.
Now restart the browser, visit about:support, you’ll notice 1/1 (Enabled by User) for Multiprocess Windows line item.
