USB-C port power capability?

Discussion in 'MacBook' started by Mike Boreham, Aug 11, 2016.

  1. Mike Boreham macrumors 65816

    Joined:
    Aug 10, 2006
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    UK
    #1
    I am close to switching from rMBP to rMB but would be grateful for info on one issue.

    My main external USB drives at present are bus powered Seagate Fast 4Tb USB3. These are RAID devices containing two 2Tb drives so I suspect the power draw is higher than usual (unsurprisingly). My late 2013 rMBP drives these quite happily connected directly.

    Any idea if the power available at the USB-C port of the rMB is similar to an rMBP such that it would power one these without needing to be plugged into the wall?

    Thanks.
     
  2. elf69 macrumors 68000

    elf69

    Joined:
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    Location:
    Cornwall UK
    #2
    The port is capable of 100 watts but I do not know if apple allows this or if they have limited it.
    --- Post Merged, Aug 11, 2016 ---
    The port is capable of 100 watts but I do not know if apple allows this or if they have limited it.
     
  3. Mike Boreham, Aug 11, 2016
    Last edited: Aug 11, 2016

    Mike Boreham thread starter macrumors 65816

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    #3
    Thanks, but I don't think 100W is right....far too much, and if you meant 100mW that is too little!

    Since posting my question I have found this link.

    The standard USB power output is 500mW (equals 0.5 W) but under certain circumstances USB 3 ports provide more...up to 900mW.(Edit, should be 1100mW)

    Reading the link again I see it says it apples to all Apple computers and displays so presumably includes the 12" Macbook. So MacBook should be same as MacBook pro.
     
  4. elf69 macrumors 68000

    elf69

    Joined:
    Jun 2, 2016
    Location:
    Cornwall UK
    #4
    USB C 3.1 can supply 100W...
    See here, from trusted reviews website:

    USB 3.0

    USB 3.0 was a big change as it brought new connector types to allow for its extra speed and power draw, with them often coloured blue to denote their prowess. USB 3.0 can run at up to 5Gbps, delivering 5V at 1.8A. It arrived in November 2008.

    USB 3.1

    The latest and greatest version of USB was released in July 2013, though uptake is still almost non-existent. It can deliver 10Gbps of throughput while up to 2A can be drawn over 5V, and optionally either 5A over 12V (60W) or 20V (100W). This is the reason the new MacBook can be powered just by its USB connection.


    Read more at http://www.trustedreviews.com/opinions/usb-type-c-everything-you-need-to-know#ZgfFMPm4Te79ce1X.99
     
  5. Mike Boreham, Aug 11, 2016
    Last edited: Aug 11, 2016

    Mike Boreham thread starter macrumors 65816

    Joined:
    Aug 10, 2006
    Location:
    UK
    #5
    Thanks for that link.

    I guess what the USB-C/3.1 max specs are and what Apple actually put in their current computers are two different things.

    All current computers supply 5V to the USB port so that would potentially be 10W max.

    But I would be very surprised if one didn't get an overload warning if you plugged a USB device requiring 2A into any of todays computers. The Apple article I linked mentions 1100mW max.

    The link implies there are possibilities for much more in future computers.
    --- Post Merged, Aug 11, 2016 ---
    The Minix USB-C hub user guide says this about power draw:

    "USB outputs are limited to 5V/600mA max. when external power adapter is not connected.

    USB outputs are limited to 5V/3A max. when external power adapter is connected.

    It is highly recommended to connect external power adapter when using external HDD or ODD.

    It is essential to connect external power adapter when using multiple ports simultaneously".

    This probably means I would need to have it plugged in when using the Seagate Fast HDs.
     

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