I've noticed that various laptop series, such as the ThinkPad P1 series, have "Mini Gigabit Ethernet" ports instead of the standard Gigabit Ethernet ports. Are there any significant differences between the two how significant is the bottleneck of the mini port?

  • 2
    What does the size or form factor of the connector have to do with it's performance? If it's a GbE port why would it not perform like any other GbE port?
    – joeqwerty
    Commented Oct 15, 2018 at 13:25
  • @joeqwerty I'm worried about the bottleneck. USB adapters, for instance, have a lower bottleneck and cannot achieve gigabit throughput, can they?
    – Adama
    Commented Oct 15, 2018 at 13:58
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    Where are you getting USB from? The specs don't say that's a USB port. The specs say that's a Mini Gigabit Ethernet port, which requires a special adapter. I don't see anything stating anything about USB in relation to that port in any of the documentation.
    – joeqwerty
    Commented Oct 15, 2018 at 14:11
  • One would assume that the mini port would be electrically identical to the full size port and that it is just a modified connector to allow the size of the notebook to be reduced further - much like how, say, USB 3 connectors such as "Micro B" are used for "pocket" USB hard disks, yet a full-size type-B connector is almost twice the height of a typical type-A connector yet is still electrically identical. i think the decision to make a smaller receptacle is purely to reduce overall device height - the holy grail of device manufacture.
    – Kinnectus
    Commented Oct 15, 2018 at 14:37
  • This question got downvoted; not certain why. I don't have hard data to merit an answer, but like previous comments, I don't think that the reduced-height port will have a performance difference as long as the chip on the inside is the same. Commented Oct 15, 2018 at 15:58

1 Answer 1


Gigabit Ethernet transports 1 Gbit/s*, no matter the form factor - twisted pair, fiber, or that proprietary "Mini Gigabit" port.

That said, a decent GbE NIC transports 1 Gbit/s per direction. Mileage with poor implementations (old cards, using PCI or USB 2.0) may vary - they still run at 1 Gbit/s but can't hold that speed continuously between frames.

(* To be exact, the bit rate is measured on top of the physical layer and includes upper layer-1 overhead like preamble and IPG but not PCS or other encoding.)

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