External Drives: Daisy Chains and Bus Power

Created on: May 11, 2013
Last updated: August 22, 2017

We often are asked if it is possible to daisy-chain multiple drives and have all of them draw power from the main system bus. The short answer is no.

Once you begin daisy chaining hard drives or SSDs, each drive in the chain will need a dedicated power supply to run reliably. Note: Thunderbolt device chains allow for the possibility of a bus-powered drive to be used as an end-chain device. For Thunderbolt 3, up to 15W of power is provided for that scenario.