If there's 10W of power through the Thunderbolt cable, why does it require an external power supply?

hello:
So if in the future I want to connect a Seagate 2.5 in HDD ( 5v power), to a Thunderbolt cable,
1-how much current can the drive load the cable?

2 What is the voltage specification on the 5v?


thanks jim

  • Asked by Jim F from Niwot
  • Jan 3, 2012
LaCie Little Big Disk Thunderbolt Series Hard Drive

LaCie Little Big Disk Thunderbolt Series Hard Drive

Product No Longer Available

1 Answer from the Community

  • Answer

    There is no +5v available on the cable. The bus power is for the cable and for the Thunderbolt interface. Each device must follow the spec, and either convert the power that is available to something suitable, or be self powered with an AC adapter.

    • Answered by Mike M from Beaverton
    • Feb 6, 2012