With the release of Firefox 54 last week, the process of making multiprocess Electrolysis available was finally completed.
Since its latest version, Firefox can use up to four processes, so users of the popular browser will be able to have better memory usage and of course better performance.
However, users who have been using the Mozilla Foundation browser for years may be disappointed to find that their browser runs in a single process.
If this is happening to you, the culprits are the plugins you've probably been using for years.
To check if Firefox 54 is using a single process, you can check your operating system's processes or check if the browser value associated with the internal setting dom.ipc.processCount found in Firefox's about:config is set to 1.
If you notice any of the above, it's time to look in Firefox add-ons to see which extension is giving the error.
Firefox provides little information at the moment, but if you install the Add-on Compatibility Reporter you will see a lot of information in the Firefox extensions panel.
In the top right corner there will be a label indicating whether multitasking is enabled or not. Below you will see a list of all your extensions and a label indicating whether or not they are compatible with electrolysis.
What you do next is up to you:
If you disable incompatible extensions, then multi-threading will be enabled in your browser, but you may also need to change the value of dom.ipc.processCount like I did.
Alternatively, you can continue to run your browser in a single process if you absolutely need a specific add-on, knowing that with Firefox 57, which will be released in November, all extensions will be migrated to WebExtensions.
