2016 MBP 13" USB C port performance

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

  1. croco_dile macrumors regular

    Jun 3, 2016
    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?

  2. Samuelsan2001 macrumors 604

    Oct 24, 2013
    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

    Jun 3, 2016
    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

    Oct 24, 2013
    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

    Jun 3, 2016
    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

    Oct 24, 2013
    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


    Jan 23, 2017
    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

    Sep 11, 2014
    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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