256GB shouldn't be RM85, at least wont be that soon.
real deal USB3+ pinout have 9 contacts, cheap ass USB2, or charging cable only have 4 pins


sauce https://en.wikipedia.org/wiki/USB_3.0

I think generally if you're looking for good or high performance thumb drive, it should be more expensive one or big in dimensions, because extra circuit for dram or dual nand chips.

Tiny one you can forget about it, the advertised USB3. 2 gen 1 or 2 is very gimmicky for non savvy person.
It's just bigger bandwidth but not about the transfer rate