Does using internal SSD storage speed up FCP?

Dear FCP Community,

This might be a dumb question, but does having all your material on an internal SSD speed up FCP, or at least keep things running smoothly with no major slow downs?

I ask because I recently finished a documentary where we had hundreds of clips (50 hours or more of footage) imported into the project, although the actual media was left in place on an external HDD, connected to my M1 Mac Mini via USB.

On occasion, FCP would become so slow as to be unusable. The only workaround we found was to reduce the number of clips in the browser, and then reimport things as and when needed.

I didn't find anything amiss when running Activity Monitor or EtreCheck, so assume that the problem might be caused by the slow speed of the USB connection and HDD - hence thinking of buying a new machine with sufficient internal SSD space to import everything into, and run the project from there.

Any thoughts would be greatly appreciated. Thanks.