macbook charging cable

yeah, saw that, but "usb c" is too general. in untold numbers of threads here and elsewhere, that whole usb c covers 3.1, 3.1 gen 2, thunderbolt 3 thunderbolt 4 and so on. it's annoying. I have too many cables that look identical, but could be bottlenecks, found only by exhaustive testing that I've been doing, trying to find what actually works at 10 gb/s and what works at 40 gb/s. another annoying disappointment- I find my ssds actually perform slower with my new air that was just manufactured last month, than with my 2012 iMac using usb 3.1 spec. Blackmagic disk tests, and amorphous disk speed tester, both machines, slower results on my m1 air. whaaaat..!? had read about possibly being software related fix. updated to Big Sur 11.2.3 just this morning, same results.

saw those. also waiting for that thunderbolt 4 hub to become available that owc shows on its website. I have so much junk here for my old MacBook Air, my old iMac desktop, etc.. and seriously have an aversion to bottlenecking as I work with storage heavily, backups and backups galore..