What you need to do is change some settings in Chrome to disable throttling of non-active windows.
Go to the address bar in Chrome and type Chrome://flags
This will bring you to the window shown below. It will warn you the stuff is experimental and such. In the Search bar type "Throttle" and it will bring up a few options, where you can choose to disable them.
Click on Relaunch.
After this, when you open multiple Chrome Windows (not tabs), and even if they are hidden behind the front active window all run at the full speed. This way I have opened 20-40 windows all processing simultaneously on my Ryzen 5950X based computer.
Hope this is helpful.