2016 MBP 13" USB C port performance

Discussion in 'MacBook Pro' started by croco_dile, Apr 25, 2017.

  1. croco_dile macrumors regular

    Joined:
    Jun 3, 2016
    #1
    According to Apple, the USB C ports on the left side of the 13" MBP are full speed and faster than the 2 right-hand side ports. Apple did not say how much faster/slower. It is also recommending that higher performance devices be used with the ports on the lefthand side.
    • MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports) supports Thunderbolt 3 at full performance using the two left-hand ports. The two right-hand ports deliver Thunderbolt 3 functionality, but have reduced PCI Express bandwidth.
      Always plug higher-performance devices into the left-hand ports on MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports) for maximum data throughput.
    I have a few questions:
    1. Do people know the difference in performance between the two sides?
    2. I have a 27" 4K monitor, is that considered high-performance? and does it matter which port I use?
    3. I also have an external Samsung SSD T1 using USB 3.1. Would there be any difference in read/write speed when plugged into left-hand side vs right?

    Thanks
     
  2. Samuelsan2001 macrumors 604

    Joined:
    Oct 24, 2013
    #2
    To be honest unless you are using a 5K screen or running a TB3 dock with many peripherals attached it or an external gpu in a PCIe box, it will make no practical difference which one you use. Most things are maxed out on TB2 speeds anyway.
     
  3. croco_dile thread starter macrumors regular

    Joined:
    Jun 3, 2016
    #3
    Thanks Sam.

    I do have a USB C hub (Hyperdrive that connects to both of the USB C ports). At the peak, I could have the monitor, 2 USB 3 drives and a SD card all connected to the hub. Probably best if I separate out the monitor and connect it to the other side.
     
  4. Samuelsan2001 macrumors 604

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    Oct 24, 2013
    #4
    The USB-C hub will mac out at 20gb/s the thunderbolt will be 20gb/s or 40gb/s with an active usb c tb3 cable below 0.5m in length. To be honest nothing you are connecting will max that out the port even all running at the same time I wouldn't worry my only issue with the hyperdrive for the MacBook pro is the low 30W pass through charging will mean its slow to charge.
     
  5. croco_dile thread starter macrumors regular

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    Jun 3, 2016
    #5
    The Hyperdrive I got (hooking up to both USB C ports) delivers 100W for charging which is more than enough for 2016 MBP, even the 15".
     
  6. Samuelsan2001 macrumors 604

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    Oct 24, 2013
    #6
    Oh wow yes just took a look at that very nice, yeah it'll have no problems running everything even a 5k screen.
     
  7. ZapNZs, Apr 25, 2017
    Last edited: Apr 25, 2017

    ZapNZs macrumors 68020

    ZapNZs

    Joined:
    Jan 23, 2017
    #7
    As I only have two 40Gbps TB3 ports, I have not personally done testing on this, but, to my understanding...

    The two less-than-40Gbps TB3 ports still support 10 Gbps USB 3.1 gen 2 (so twice the theoretical peak transfer speed of 3.1 gen 1 [formally USB 3.0.]) IIRC, the T1 uses USB 3.1 gen 1, so it is capped at 5 Gbps as its maximum theoretical peak, and the max running speed of the T1 is something like 470 MB/s. And IIRC, a USB-C 3.1 gen 1 5Gbps connection can support a single 4k display @ 60hz (which more or less saturates most of available bandwidth.) So they should have absolutely no issues with either the monitor or the SSD (If I am wrong please correct me!!!)

    My guess is when Apple says to always plug higher performance devices into the left-side ports, they are referring to things like RAID0 SATA SSDs, eGPUs, or NVMe SSDs that could potentially utilize a large majority of the available 40 Gbps from the full speed TB3 side?
     
  8. killawat, Apr 25, 2017
    Last edited: Apr 25, 2017

    killawat macrumors 65816

    Joined:
    Sep 11, 2014
    #8
    Correct for the most part. The USB Gen doesn't need to be considered, as long as DisplayPort Alt Mode is available on the port.
     

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