I tested on my cpu 3970x threadripper which is 32cores used 6% cpu when uploading a 4gig file using filezilla. When I get some time I can test on my i5 laptop and a ryzen 2400g and see if theres a huge difference when uploading the same exact file.
I tested my laptop which has a i5-7200u pretty weak cpu I might add used between 62%-100% cpu while uploading 4gig file.
I blew off the dust on my x5675 dual socket cpu when uploading the file it used 14% cpu 4gig file.
Id like to see something an older cpu can do faster then a new cpu, From my experience there is nothing faster with an older cpu when compared to a new. That is why we upgrade from older cpus in general. The only thing an old cpu can do is use more electricity with less efficiency.