external dvd drive for macbook pro retina

Discussion in 'MacBook Pro' started by zarzonis, Apr 8, 2014.

  1. zarzonis macrumors member

    Joined:
    May 3, 2013
    Location:
    Greece
    #1
    Hi, i have a macbook pro retina 15" late 2013 model and i want to buy an external dvd drive. I don't use it so much but there are times i need it. I would like to hear some suggestions. I don't want to buy apple's superdrive, because it's too expensive. I need it just to read or write some files and sometimes to watch a movie. I saw some online but many of them have 2 usb ports. Why is that?
     
  2. 5to1, Apr 8, 2014
    Last edited: Apr 8, 2014

    5to1 macrumors regular

    Joined:
    Mar 9, 2008
    #2
    USB 2 standard prescribes for 500mA (2.5w) limit on the maximum a device can draw. While thats sufficient for reading a disc, its not likely to be sufficient for writing. Therefore some drives provide a dual headed cable, where the second cable is used to draw additional current from a second USB port.

    There are instances where ports will provide less then 500mA and some if you're lucky that will provide more. The latter is particularly the case on newer machines, where it became clear USB devices and their power requirements had moved on. Your later rMBP will have a USB3 port, so can provide more power, but I'm unsure if it will still limit the output to spec when it detects a USB 2 device has been plugged in.

    You should only really need the second cable connected when writing, so assuming this is not going to be often, the easiest thing to do is get an extension which will allow you to connect to the port on the other side of the laptop. If you're writing more often, it may be best to get a drive with an external PSU.
     
  3. yjchua95 macrumors 604

    Joined:
    Apr 23, 2011
    Location:
    GVA, KUL, MEL (current), ZQN
    #3
    In some occasions the external DVD drive may not have enough power to operate, so you need to connect both USB cables in order to get sufficient power.
     
  4. zarzonis thread starter macrumors member

    Joined:
    May 3, 2013
    Location:
    Greece
    #4
    Thank you for your answers. And how apple's SuperDrive works with only one cable?
     
  5. 5to1 macrumors regular

    Joined:
    Mar 9, 2008
    #5
    Generic drives tend to use which ever parts/mechanism are cheapest. Apple have probably engineered (or rather asked the supplier to) their drive to work with the power available on the USB ports of their machines. Other generic drives may also do this, try searching the forums for third party drives known to work with one cable on your machine.
     

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