thanks! so updating the Os and imovie is 2 things, but the stuff with Rosetta is another? or updating the aforementioned should help with that? I'm literally already sitting on the erased mac ready for the courier to pick it up haha... still wanting to find a solution. Classic
The first version to support Apple Silicon natively was iMovie 10.3 but that was 2021 already so it's very unlikely you're running rosetta.
One thing I can think of is maybe you're running low on RAM and have little space on the internal drive.
(Although 16GB should be plenty for simple video editing, i had the same config as you 16/512).
However if by some weird reason you're running out of RAM, the system pages the RAM to SSD.
If SSD is full, it runs slower and makes the whole process more annoying.
But i've edited 4K footage on FCPX on a 13" M1 16/512 and it was absolutely fine
It makes absolutely zero sense that a 2014 could run better, even if it were a maxed out 15".
it has much slower CPU, slower RAM and slower SSD and slower GPU.
it's just much slower in every single aspect.