Here is the command line, not sure if it is gonna help Someone may need to debug the extension to understand why it doesn't let Firefox release memory when you close the relevant tab. You should be able to cross-reference the PID with the tool you're using. My comment will make more sense if you add the Command Line column to your Details view in the Windows Task Manager. I am not being clear? it is a Firefox process Firefox.exe Is there anyway that can make the companion app uses all processes for Firefox, so it will distribute the CPU usage to all cores, and if used a high memory it will be distribute the memory to all process and will be easier to clean. Usually when I kill a Firefox process that is not responding, it will crash a few tabs and they can be refreshed after that. When finished, if I killed this Firefox process to clean memory, cause it will just accumulate the memory in that specific process, all the tabs in the Firefox will crash and can't be refreshed, until I close Firefox and open it again. It is the process that almost doesn't uses GPU memory. It seems that this process is the core process for Firefox, although it is a sub-process. Ans cause it does not take advantage of all the CPU cores it is very slow, and uses high memory for that process and will make all tabs in Firefox slow. I am using Video Download Helper with companion app, when downloading videos, the DownloadHelper will uses only one process of Firefox with very high CPU and memory usage.

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