Connections used to be easy. USB, Firewire, Display Port, no problem. Now we have USB 3.1, USB-C, and Thunderbolt 3. Not so easy because they all can share the same cable and use the same transfer protocols… or not. It depends. Who knows?
To understand the differences between these three, we need to understand the different levels of USB and how they’ve been renamed. The renaming is a big part of the confusion.
A USB By Any Other Name
The main thing that USB has done in the name change game is now the connector type is designated by a letter and the transfer protocol is designated by a number.
USB Type A is the original rectangular USB connector that we’ve been plugging into our computers for years. USB Type B is the other end of the cable that plugs into the peripheral and includes the mini and micro versions and even the Apple Lightning cable for the iPhone and iPad.
The USB Type A connector has been been compatible with USB 1.1, 2.0, and 3.0. However, the USB Type B connector changed for USB 3.0. Except now, USB 3 is called USB 3.1 Gen 1. Still with me?
USB 3.1 Gen 2
Along with USB Type C connector, USB also came out with USB 3.1 Gen 2 which was a big leap forward. Not only did it double Gen 1 speeds to 10Gbps, it also increase the amount of power a device can draw from the host. While USB 2.0 & 3.1 could power smaller devices like portable drives and phones, USB 3.1 Gen 2 is capable of powering laptops and monitors.
The Newest USB
Just last month, USB-IF finalized the next upgrade, USB 3.2. This will, of course, utilize the USB Type C connector. The only real feature of the upgrade is doubling the maximum speed from 10Gbps to 20Gbps. It will probably be 2018 before we see any new hardware sporting USB 3.2.
|USB Type||Top Speed||Cable Configuration||Max Power Output||Power Direction||Year Released|
|USB 1.1||12Mbps||Type-A to Type-B||N/A||N/A||1998|
|USB 2.0||480Mbps||Type-A to Type-B||5V, 1.8A||Host to peripheral||2000|
|5Gbps||Type-A to Type-B||5V, 1.8A||Host to peripheral||2008|
|10Gbps||Type-C both ends, reversible plug orientation / Type-A to Type-C (compatible)||20V, 5A||Bi-directional / Host to peripheral (compatible)||2013|
|USB 3.2||20Gbps||Type-C both ends, reversible plug orientation / Type-A to Type-C (compatible)||20V, 5A||Bi-directional / Host to peripheral (compatible)||2017|
The Rise of USB-C
Enter USB Type C, more commonly called UBS-C, and this is where things get really complicated. The first thing understand about USB-C is that it only describes the connector type. A USB-C port can be USB 2.0, USB 3.1 Gen 1, USB 3.1 Gen 2, or Thunderbolt 3. It all depends on the specs of the port and on the cable. Yes, there are many different types of USB-C cables.
USB Type-C ports can support a variety of different protocols allowing you to have adapters that can output HDMI, VGA, DisplayPort, or other types of connections streamlined into a single type of port.
The connector itself is a big improvement. It is only slighting larger than the micro USB connector so it will work on small peripherals and even mobile phones. Unlike previous versions of USB, it has the same connector on both sides so you can plug in either side.
One of the biggest physical improvements took a page from Apple’s Lightning connector and is able to plug in whether the cable is flipped or not making it extra easy to use. Even though you had a 50/50 chance of connecting the old USB cable correctly, it always seemed like it was upside down 80% of the time.
Better Power Handling
The old USB cables only allowed power to flow from the Type A connector to the Type B connector. UBS-C is bi-directional, meaning the power flows both ways through the cable. This means a laptop can be powered by USB-C at the same time as supplying power to a peripheral.
As we mentioned with the USB 3.1 Gen 2, USB-C handle can handle up to 100 watts of power. Most laptops require between 45w and 85w so they can be charged via their USB port like phones and tablets.
Thunderbolt, co-designed by Apple and Intel, is a superset of capabilities all rolled into one connection. For Thunderbolt 1 & 2, the standard Mini DisplayPort was used. With Thunderbolt 3, they switch to the USB-C connector which will most likely make USB-C the standard universal connector moving forward.
|Revision||Top speed||Port Type||Super Set of||Year Released|
|Thunderbolt||10Gbps||Mini DisplayPort||Mini DisplayPort||2011|
|Thunderbolt 2||20Gbps||Mini DisplayPort||Thunderbolt||2013|
|Thunderbolt 3||40Gbps (short or active cable) 20Gbps (long, passive cable,)||USB-C||Thunderbolt 2 (adapter required,) DisplayPort, PCIe 3rd Gen, USB 3.1 Gen 2||2015|
Thunderbolt 3 Rundown
- The Mini DisplayPort connection type has been ditched in favor of a USB-C connection type.All Thunderbolt 3 cables will work as USB-C cables.
- All Thunderbolt 3 cables will work as USB-C cables.
- Not all USB-C cables will work as Thunderbolt 3 cables.
- Thunderbolt 3 has a top data transfer speed of 40Gbps as long as the cable is 0.5m (1.6 ft.) or shorter.
- For 1m (3.2 ft.) or longer cables, Thunderbolt 3 supports passive (cheaper) ones that have a top speed of 20Gbps, and active cables (more expensive) that retain the 40Gbps speed.
- Thunderbolt 3 is backward-compatible with earlier versions of Thunderbolt, but due to the new port type, adapters are required to use legacy Thunderbolt devices.
- Any USB-C device (like a Google Pixel) plugged into a Thunderbolt 3 port will function normally.
- Since Thunderbolt 3 devices use discrete Thunderbolt chips to function, they will not function if plugged into a USB-C port.
One Port for Everything
In addition to transferring data at up to 40Gbps, Thunderbolt 3 has the bandwidth to drive two 4K monitors, charge your devices, and pump music to your external speakers, at the same time.
There are a myriad of multi-port docks available for Thunderbolt 3 contains all of the various ports which are especially useful for new MacBook Pro owners since they removed all the other ports. But, like it’s predecessors, Thunderbolt 3 has the ability to daisy-chain up to six devices together.
We are just seeing the beginning of what USB-C is capable of. With the adoption by Thunderbolt 3 of the connector, it has an excellent chance of becoming the default universal connector for most devices moving forward. The transition will take a little time, but eventually, we will have one type of connector to connect all of our devices to each other and our computers.