Firefox demands more memory with each new release and such is the case with their multiprocessor 'feature' that opens 5-6 firefox.exes. Each firefox.exe eats up your system memory and for me there isn't any notable speed increase. If you want to disable this so you only have one firefox.exe then in the Firefox location field put:
Thanks for this, Firefox sometimes takes up a lot of the CPU percentage for only having 2-3 tabs up. Some people might say it's because of a lower-end PC but at the same time… It's just a browser, it should be simpler than other programs.