Whenever I reinstall Windows and install FireFox on the fresh operating system, the FireFox installer automatically installs the 32-bit version of FireFox and I have to reinstall the 64-bit version if I notice or remember. My system is not that low on resources, either. I guess 8 GB of RAM and a 3.8 GHz dual core CPU should be enough for the 64-bit version of FireFox. It is obvious that installing the 32-bit version on computers with enough resources does not allow FireFox to make the best use of the available resources and therefore delivers sub-optimal performance.
I wish the installer would be modified to better identify the system type and resources, or at least options be made available to users to choose from. Additionally some optional features could be activated or changed by the installer to enhance the performance based on system properties, such as the use of hardware acceleration, which seems to be off by default.
I should also mention that FireFox performance and speed has greatly improved recently and after being away from FireFox for a while, although I tested and retested FireFox to check for improvements during this time, I have returned to using it again on a daily basis as my default browser both on desktop and mobile devices. I would like to sincerely thank the developers and I hope FireFox will become the most widely used browser once again.
Take a look https://forums.mozfr.org/viewtopic.php?t=152875
About hardware acceleration, which seems to be off by default
Firefox's performance settings
Use hardware acceleration when available, for me, it's not disabled by default