Thunderbolt 3 and USB-C: The Only Port your Next Computer Needs

Alex Wulff
5 min readAug 7, 2017


We are in the midst of a global transformation. I’m not talking about the Earth’s climate, or politics — I am talking about ports.

Four years ago, USB-A, the port you would think of when someone says USB port, was truly ubiquitous. Every computer produced at the time had one or multiple, and the newly introduced USB 3.1 standard promised lighting fast data transfers of 10 Gbps (a full 20 times faster than the arcane USB 2.0 standard).

An assortement of USB-A flash drives

Fast forward to today, and the USB 3.1 standard is still the go-to. Many of the newest hard drives, game consoles, and phone chargers all ship with a USB-A 3.1 port.

Around the same time the 3.1 standard was being developed engineers also started work on USB-C. USB-C was billed as smart, safe, fast, and future proof. As I will discuss, it delivered on almost all of these promises. This port will already be familiar to you if you have a recent MacBook model or the Samsung Galaxy S8.

The iconic 1998 iMac

The Apple 1998 iMac was the first computer to ditch older communications standards such as ADB. As these old standards faded into oblivion, USB’s popularity skyrocketed when semiconductor companies like Intel threw their full support behind USB. The same transition is currently happening with USB-C, and Apple is leading the charge once more. Their 2015 MacBook was the first mainstream computer to ship with nothing but a USB-C port, and Apple solidified their commitment to USB-C by releasing the 2016 MacBook pro with 4 USB-C ports and no USB-A.

A new connector style is all well and good. USB-C is fully reversible, connections make a nice solid click, and the connector stays in place. However, what really makes USB-C special is something called Thunderbolt. Thunderbolt is a standard developed by Intel in cooperation with Apple. Most MacBooks/iMacs made in the last four years sport a Thunderbolt 2 port.

Thunderbolt 1/2 port

Thunderbolt 1 and 2 took on Mini DisplayPort as their connector of choice. If you’ve ever seen the above plug on your computer before, chances are it’s a Thunderbolt 2 port. Thunderbolt has a few key advantages over USB, mainly increased data speeds and power delivery capability. Their limited adoption across a limited number of devices means that Thunderbolt 1 and 2 will also fade into oblivion before the might of Thunderbolt 3.

Thunderbolt 3 is the standard that will truly make USB-C a port for the ages. Thunderbolt 3 expands on USB-C’s capabilities by promising up to 40 Gbps data speeds. Thunderbolt 2 sports a very respectable maximum transfer rate of 20 Gbps, but no one other than Apple used it.

Now might be a good time to clear up some semantics. USB-C is only the port style adopted by Thunderbolt 3. Not all USB-C ports are Thunderbolt 3 ports, but all Thunderbolt 3 ports are USB-C ports. For example, Apple’s 2015 MacBook has one USB-C port, but this port does not support Thunderbolt 3 data transfer speeds. Thunderbolt 3 is a trademark owned by Intel whereas USB-C is a minimum standard defined by the USB Implementers Forum. From here on out I will be using the two terms interchangeably; just know that they are different.

I still have yet to make a solid case as to why Thunderbolt 3 is such a big deal. To remedy this, I present to you the LG 5K UltraFine Display. You can connect the display to your Thunderbolt-3-enabled computer (works best with a MacBook Pro/iMac) using just a regular USB-C cable. As the name implies, this is a 5K display with over 14.7 million pixels. It also features three normal USB-C data ports on the back (not Thunderbolt 3) that each support 5 Gbps data transfer speeds.

In addition, the LG 5K UltraFine has integrated stereo speakers. The icing on the cake is that you can even charge your laptop at a full 85W (the wattage of Apple’s most powerful MacBook pro charger) while simultaneously transferring data. All. Through. One. Port. Oh, and the 15-inch MacBook Pro 2016 can handle two of them.

The display itself is certainly an engineering marvel, but what allows it to really shine is the Thunderbolt 3 standard. For the same functionality with conventional standards you’d need:

  • A DisplayPort cable/adapter for audio and video
  • A USB hub for more USB ports
  • A separate charger

You can also buy Thunderbolt 3 hubs on Amazon that provide SD card slots, USB-A connectors, HDMI output, passthrough charging, and more in one small package. I bought the HooToo Shuttle for my MacBook — it has three USB 3.1 ports, HDMI out, USB-C charging passthrough, and an SD card reader.

Another important improvement of USB-C (this time I’m just talking about the USB-C standard, not Thunderbolt 3) is power delivery. The 85W-capable charger that ships with your 15” MacBook Pro is also capable of delivering the correct voltage to your Samsung Galaxy S8’s USB-C charge port. The USB-C standard mandates that high-wattage chargers such as those that ship with USB-C computers must be capable of changing their voltage level to support other devices.

This is all part of the goal to make a universal port. If damaging your phone was possible by plugging it into a laptop charger, then the port wouldn’t truly be universal. Unfortunately, the measly 5W or 10W chargers that ship with your USB-C phone are not capable of delivering the required voltage and current demanded by laptops — plugging one into a laptop just won’t do anything. Chargers such as the Dart-C promise to bridge the gap between the two systems by offering high-wattage adaptable charging in a small form factor.

I fully admit that USB-C and Thunderbolt can be maddeningly confusing. Learn to love and understand this versatile standard, though, as I anticipate that you’ll be seeing much more of it in the coming years.

Let me know what you thought of this post. To see more of my work check out my website,, and my Medium page.



Alex Wulff

I'm a Harvard student, maker, and radio enthusiast. Check out my book on radio communications at and my website at