What is USB-C, USB4, Thunderbolt 3, Thunderbolt 4? – MacHollywood | Your Premier Tech Partner

What is USB-C, USB4, Thunderbolt 3, Thunderbolt 4?

Posted by Phil Baker on


There is a lot of confusion still surrounding the name and what is the appropriate connection when dealing with what most know as, the USB-C Port. Is it Thunderbolt 3? Can I use a USB-C charge cable to connect a data device? “But I thought they are the same size and shape?”  To clarify this, lets layout all the different names and looks of these confusing ports.


  • Thunderbolt 4
  • Thunderbolt 3
  • USB-C
  • USB4




Wow right? Nowhere closer to knowing what when where or how with these huh?  “How do you tell the difference?!” is something I hear daily, maybe even hourly some days. Don't worry, I'll go into a little bit of the basic details.


Thunderbolt 3 combines Thunderbolt, USB, DisplayPort and power via a single USB-C connector and Thunderbolt 3 and Thunderbolt 4 are proprietary; as in machines/drives/interfaces ALL MUST have this Thunderbolt symbol to use them. In most cases, things like drives that come Thunderbolt 3 would also come with the ability to connect via a plain USB-C Port, however this is not always the case. Thunderbolt carries a faster speed, normally being around 1800mb/s on things like the Lacie Rugged SSD Pro, where as the Lacie Rugged SSD (USB-C Option) carries an estimated speed of up to 950 mb/s. These are also the way to connect Apple Thunderbolt and XDR Displays to your other Mac devices, such as your Mac Mini, MacBook Pro's, and MacBook Air's.  A good rule of thumb would be to check if you have the Thunderbolt symbol (next to the text of the pictured port above) on your machine to ensure that addition can connect to the computer. If you don’t have that symbol, make sure to triple check that the desired source can operate on USB speeds/connections.


Another quick tip, you CAN use a Thunderbolt 3 cable in place of a USB-C cable, You CAN NOT use a USB-C cable in place of a Thunderbolt 3 cable. This is because the Thunderbolt 3 cable is rated higher with data transmission.  The OWC Thunderbolt 4/USB-C Cable fully supports all the awesome features of Thunderbolt 4 and USB4, while also being fully backward compatible with Thunderbolt 3 and USB 3 hosts and devices, but this is still too new of a cable for me to truly speak on so I will do that at a later time.


While the reasoning above is the way things normally work in the tech world, there are always a bunch of confusing exceptions to these rules. In example, the LG 4K and 5K Displays (and most others) now utilize the USB nature of this port and not Thunderbolt 3. This has plagued many with lots of confusion else where in their timeline of purchases. Making sure which of the above connections the manufacturer states the unit is made for is the only real way to mitigate any confusion, compatibility issues, or loss of funds because you simply can’t use your device. If you are leaving me today with a better understanding of this 4 legged creature, I’ve done my job! If you are leaving more confused than before, give us a call or stop in and we can try our best to give you the correct information regarding the compatibility of the requested units!


Share this post

← Older Post Newer Post →

Leave a comment

Please note, comments must be approved before they are published.