Powering external drives from a single USB-C/Thunderbolt 3 port - Mac Mini


macrumors newbie
Original poster
Jul 10, 2019
Hi all,

My second post today...can you tell I’ve just bought a new computer!

My question is:

Will a single USB C/Thunderbolt 3 port on the 2018 Mac Mini provide enough power for 4 standard USB external hard drives (WD My Passport types) through an UNPOWERED USB-C or Thunderbolt 3 hub? Or should I buy a powered one? The cost difference is significant...of course.

Many thanks


macrumors regular
Nov 10, 2016
Theoretically that should work. USB-C is rated for 15W device power, and a drive backwards compatible with USB 2.0 pulls less than 3W. Allowing a watt or two for the hub should leave just enough for four low power drives.

In practice I dislike pushing specs that close to the limit.


macrumors 6502a
Jan 4, 2015
Key West FL
USB3 devices can pull more. The original spec was 3.75w and many pull more, often in the 5w range. Given that the hub itself will consume some power for its own circuits, the hub plus 4 USB3 drives would very likely challenge a USB-C port even if it meets the full spec power level and my very likely exceed its ability.


macrumors P6
Feb 20, 2009
I doubt a single port can power FOUR external platter-based drives.

Buy a decent powered USB3 hub.
Doing this will save you A LOT of trouble.