USB 3.0 Speeds with Thunderbolt Dock

Discussion in 'MacBook Pro' started by Pauly 6 String, Aug 15, 2016.

  1. Pauly 6 String macrumors member

    May 3, 2015
    Hello. I have a Late 2011 MacBook Pro with Thunderbolt and USB 2.0. I have a Belkin Thunderbolt Express Dock that has 3 USB 3.0 ports. Connected to them I have a Segate USB 3.0 External Drive.

    The Read/Write speeds are around 40MBps read and write. Plugged directly into a MacBook Air that has 3.0 I get just over 80 MBps. Is this normal? Should I get higher speeds? Isn't USB 3.0 supposed to be around 640MBps? I understand that the dock may not do better than 320MBps but I was hoping to get a bit closer.

    Thanks for any light that can be shed on this for me.
  2. nbourbaki, Aug 15, 2016
    Last edited: Aug 15, 2016

    nbourbaki macrumors regular

    Apr 19, 2015
    I have a late 2013 rMBP and a CalDigit TB2. With my Seagate Backup Slim 2TB drives I get 86.4MB/s write and 104.3 MB/s read connected to the TB2 as reported by BlackMagic Disk Speed test.

    How is your drive formatted? If the drive isn't formatted OS X Extended (Journaled), get a reasonably fast USB 3 flash drive, format it to OS X Extended (Journaled) and run the BlackMagic Disk Speed test on the USB flash drive.

    As far as how fast, remember the external Seagate drive you have connected is probably a 5400rpm laptop drive. It's not going to be able to saturate the USB 3.0 bus.

    Also, for testing purposes you need to use the BlackMagic Disk Speed Test. If you're comparing transfer to and from a 5400rpm drive (2011 MBP) against the flash drive in the MBA, it's apple to oranges. BlackMagic takes the host drive out of the equation.
  3. Pauly 6 String thread starter macrumors member

    May 3, 2015
    Thanks for your reply. It is a desktop drive (3.5", 5,900 RPM) formatted to OS X Extended and I have been using Black Magic.

    I am not using a flash drive but using the MacBook Air as it is USB 3.0 to compare to my older MacBook Pro which is 2.0 yet using Thunderbolt Dock. It seems like the Dock is really slowing things down which I have heard is common.
  4. Richdmoore macrumors 68000


    Jul 24, 2007
    Troutdale, OR
    I recall the belkin thunderbolt 1 dock usb's ports were 1/2 speed USB 3.0 (2.5 vs normal 5). I think they fixed it with the thunderbolt 2 version of the dock. (I was looking at docks awhile ago, and I chose the Caldiget dock because it had full speed USB 3.0.)

    Next is USB 3.0, which many Mac users will find interesting as the Express Dock provides one of very few ways to add USB 3.0 capabilities to pre–2012 Macs. Unfortunately, Belkin’s implementation of USB on the Express Dock caps the data transfer rate at 2.5 Gb/s, half of the technology’s current theoretical maximum of 5.0 Gb/s. Even at the slower speed, however, USB 3.0 on the Belkin will still noticeably outperform USB 2.0, making the product worth it for owners of older Macs who desire access to current USB 3.0 accessories.

    I don't think the reduced speed would affect traditional hard drives however, as they are pretty slow in general vs SSD drives.
  5. Pauly 6 String thread starter macrumors member

    May 3, 2015
    So it is more the limitation of the traditional drives speeds than the Dock?


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