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Thunderbolt Port Explained — Everything You Need To Know

Hey there! If you‘re like me, you probably have seen those Thunderbolt ports on your laptop or desktop PC and wondered, "What‘s the big deal about Thunderbolt ports anyhow?" Don‘t worry, I‘ve done the research so you don‘t have to!

In this guide, I‘m going to explain everything you need to know about Thunderbolt – what it is, why it‘s useful, how it works, and more. You ready? Let‘s dive in!

What Exactly Is Thunderbolt?

Thunderbolt is a hardware interface technology developed by Intel and Apple that allows you to connect external devices to your computer using a Thunderbolt port. Essentially, it provides a super fast and versatile connection standard.

According to Intel, each Thunderbolt port combines the PCI Express (PCIe) and DisplayPort interfaces into a single USB-C style port. This means Thunderbolt ports can carry both data and video signals.

By tapping directly into PCIe, Thunderbolt gives connected devices direct access to your computer‘s graphics card and processor. This enables blazing fast transfer speeds and the ability to attach hardware like external GPUs that usually have to be connected internally.

A Quick History of Thunderbolt

Now before Thunderbolt, connecting devices to your PC could be a messy tangle of cables. Let‘s take a quick look at how we got to today‘s sleek Thunderbolt ports:

  • 2009 – Intel unveils a prototype interface called Light Peak at the 2009 Intel Developer Forum. It promised bi-directional 10Gbps transfers over a single cable.
  • 2010 – Apple joins the project to develop Light Peak into a commercially viable standard. Their goal was to simplify laptop connectivity through a single dynamic port.
  • 2011 – The first generation of the technology launches as Thunderbolt on Apple computers. It uses Mini DisplayPort connectors but is compatible with existing displays.
  • 2013 – Thunderbolt 2 arrives and doubles the maximum bandwidth to 20Gbps per channel. Speeds are starting to get seriously fast!
  • 2015 – Thunderbolt 3 boosts the speed again to a blistering 40Gbps per channel. It also adopts USB-C connectors. This was a huge upgrade!
  • 2019 – Thunderbolt 4 refines compatibility and minimum performance requirements while keeping the 40Gbps throughput per channel.

Pretty cool to see how much Thunderbolt has evolved! Each version is backwards compatible too so you can use older devices on newer Thunderbolt ports.

Why Thunderbolt Ports Are Important

You might be wondering…why does Thunderbolt matter when we already have USB?

Here are some key advantages that make Thunderbolt ports so beneficial:

Blazing Fast 40Gbps Speeds

Thunderbolt 4 handles up to 40 gigabits per second (Gbps) per channel. That‘s a max total bandwidth of 80Gbps when using both channels!

To put this into perspective, even Thunderbolt 1 from 2011 was twice as fast as USB 3.0 ports which were just 10Gbps.

Single Cable Docking Stations

With the right docking station, a single Thunderbolt 4 cable can provide charging, USB ports, Ethernet, display connections, SD card readers, and more all from one port on your laptop. Talk about a clean desktop!

External GPU Support

This is a big one for gamers and creative pros. An external GPU (or eGPU) allows you to connect a powerful desktop graphics card to a Thunderbolt laptop. This can provide a major boost for gaming or video production.

Daisy Chaining Devices

Thunderbolt supports daisy chaining up to 6 devices together on one cable. So you can connect a display, hard drive, and printer together in a chain. Super handy!

As you can see, Thunderbolt provides some major expansions in capability compared to regular old USB. The extra speed and versatility is really nice if you do any kind of intensive work or gaming on your computer.

How Do Thunderbolt Ports Actually Work?

Thunderbolt ports have two main parts – the controller and the physical port itself.

The controller is a small chip that handles directing all the fast PCIe and DisplayPort data carried by Thunderbolt. It enables those super high speeds.

This Thunderbolt controller then connects to the physical port on your computer. Earlier Thunderbolt 1 and 2 ports used Mini DisplayPort connectors. Thunderbolt 3 and 4 use USB-C style ports.

When you connect a Thunderbolt peripheral, the controllers on each end talk to each other. They negotiate the optimal connection speed based on the Thunderbolt versions they each support.

From there, the Thunderbolt controller gives connected devices direct access to the PCIe lanes and DisplayPort connections coming from your PC‘s graphics card and processor.

Essentially, the Thunderbolt controllers extend these internal high-speed buses to external devices. This is what gives Thunderbolt ports such unique performance capabilities beyond regular USB.

Thunderbolt Versions and Speeds

There have been four generations of Thunderbolt technology so far, each faster than the last:

Version Release Date Max Speed Connector
Thunderbolt 1 2011 20Gbps total Mini DisplayPort
Thunderbolt 2 2013 40Gbps total Mini DisplayPort
Thunderbolt 3 2015 80Gbps total USB-C
Thunderbolt 4 2019 80Gbps total USB-C

As you can see, the total possible Thunderbolt bandwidth has increased 4x over the various versions! The newer versions are all backwards compatible too so you can use older Thunderbolt devices on newer ports.

However, to achieve the maximum speed both devices need to support the newest generation available to them. For example, a Thunderbolt 2 laptop will drop to Thunderbolt 1 speeds when connected to a Thunderbolt 1 external hard drive.

Make sense? Let‘s break down the key specs of each version:

Thunderbolt 1

Released in 2011, the very first Thunderbolt standard allowed a total bandwidth of 20Gbps. This was double the speed of USB 3.0 at the time!

The ports used Mini DisplayPort connectors to maintain compatibility with existing displays on Apple devices.

Thunderbolt 2

In 2013, Thunderbolt 2 came along offering 20Gbps on each of its two channels for a total of 40Gbps.

This allowed activities like video editing and backups to run smoother. Thunderbolt 2 used the same Mini DisplayPort ports.

Thunderbolt 3

This was a huge leap forward in 2015. Thunderbolt 3 kicked the individual channel speed up to 40Gbps. This allowed for a total bandwidth of 80Gbps.

Thunderbolt 3 also introduced USB-C style connectors. This was great because USB-C ports are small and universal across devices.

Thunderbolt 4

Released in 2019, Thunderbolt 4 keeps the blazing 40Gbps per channel throughput of Thunderbolt 3.

The main improvements are mandatory support for peripheral features like charging laptops and waking devices from sleep. Thunderbolt 4 ensures consistent performance across devices.

Thunderbolt vs. USB-C – What‘s the Difference?

Now you may have noticed that Thunderbolt 3 and 4 use USB-C style connectors. But aren‘t they different interfaces?

Yep, this is where things can get a bit confusing. Here‘s a quick rundown of how Thunderbolt and USB-C compare:

  • Speed – USB 3.2 Gen 2×2 matches Thunderbolt 3‘s 40Gbps but most USB-C ports are slower Gen 1 or 2.
  • Power Delivery – Both support charging laptops up to 100W.
  • Displays – Thunderbolt natively works with DisplayPort monitors. USB-C needs "Alt mode".
  • PCIe access – Thunderbolt gives direct PCIe access for external GPUs, etc. USB-C does not.
  • Cables – Passive USB-C cables are cheap. Active 40Gbps Thunderbolt 4 cables run 0.5 to 2 meters.
  • Daisy chaining – Thunderbolt can daisy chain up to 6 devices per cable. Not doable over plain USB-C.

So in summary, Thunderbolt ports provide all the capabilities of USB-C along with PCIe and DisplayPort support for advanced performance.

You can identify Thunderbolt ports by looking for a small lightning bolt symbol next to the port. Many laptops have both Thunderbolt and regular USB-C ports. Apple‘s MacBooks use Thunderbolt 4 exclusively now.

What Can You Connect Via Thunderbolt?

Now that you understand the basics, what can you actually use these Thunderbolt ports for? Here are some of the most common uses:

Docking Stations

A Thunderbolt dock lets you connect a single Thunderbolt cable to your laptop to gain access to extra ports for charging, USB, displays, Ethernet, audio, SD card readers, and more. I love how clean this looks on a desk!

External GPUs (eGPU)

An external GPU enclosure allows you to connect a full desktop graphics card to a Thunderbolt laptop. Gamers can see huge performance gains in intensive games. Video editors and 3D modelers benefit from the extra GPU horsepower too.

High-Resolution Displays

Since Thunderbolt uses the DisplayPort standard, it easily connects to high resolution 4K, 5K, and even 8K displays. You can even run dual 4K monitor setups flawlessly with Thunderbolt ports.

Network Attached Storage (NAS)

For large media files and backups, Thunderbolt NAS devices provide tons of super fast storage perfect for the high bandwidth Thunderbolt offers. No more USB 2.0 crawl!

Audio Interfaces

Recording musicians appreciate Thunderbolt audio interfaces for their extremely low latency. They connect digitally over Thunderbolt rather than USB for reliable high performance.

And More…

Those are just a few examples. You‘ll also find Thunderbolt used for HD camcorders, iPhone video rigs, memory card readers, scientific instruments, and other specialty peripherals that need the speed.

Which Companies Support Thunderbolt?

While not quite as common as USB ports yet, most major computer manufacturers now support Thunderbolt:


As a co-developer of Thunderbolt, Apple has fully embraced the standard. All recent Macs include Thunderbolt ports, with the newest MacBook Pro 16" and Mac Studio rocking Thunderbolt 4.


Many of Dell‘s flagship laptops and desktops contain Thunderbolt 3 or 4 ports including the XPS line, Alienware gaming PCs, Precision workstations, and Latitude business laptops.


A wide range of Lenovo devices offer Thunderbolt connectivity including ThinkPad, ThinkBook, Legion, and IdeaPad laptops along with ThinkStation desktops.


Select HP laptops and mobile workstations have jumped on board with Thunderbolt ports including the Spectre, Envy, ZBook Studio, and Elite Dragonfly models.


Asus computing products like the ProArt, Zenbook Pro, and Studiobook creative laptops along with ROG and Flow gaming laptops include Thunderbolt support.

Tips for Using Thunderbolt Ports

Here are some tips and best practices when using Thunderbolt ports and devices for the best experience:

  • Carefully check for the Thunderbolt lightning icon before purchasing a device or cable to ensure compatibility. USB-C ports may not support Thunderbolt.
  • Update your computer and device firmware for maximum compatibility and to resolve any issues. Keeping up-to-date is key.
  • For fastest speeds, match Thunderbolt versions on connected devices when possible. Newer devices will step down to older Thunderbolt gear‘s speed.
  • Consider a Thunderbolt dock to massively expand connectivity from a single port. Docks are great for minimalist, tidy workspaces.
  • Daisy chain Thunderbolt devices together to conserve ports. Connect the device with the highest bandwidth requirement like a display first.
  • Look for Thunderbolt 4 ports and cables for maximum future-proofing. The extra headroom will accommodate future Thunderbolt evolutions.
  • Use active Thunderbolt 4 copper cables up to 2 meters for 40Gbps speeds. Passive cables are cheaper but limited to 20Gbps.

Closing Thoughts

I hope this guide gave you a helpful overview of how Thunderbolt ports work and the key benefits they offer compared to regular USB-C.

The bottom line is that Thunderbolt provides extremely fast 40Gbps speeds perfect for external GPUs, docks, high-res displays, and performance peripherals. While not as common as USB yet, Thunderbolt adoption is increasing across major manufacturers.

With both USB4 and Thunderbolt 4 pushing connection speeds faster, the future looks bright for universal high-performance ports. Just remember to look for that Thunderbolt lightning symbol to gain access to that next-level speed and versatility!

Let me know if you have any other questions about Thunderbolt ports. I‘m always happy to chat more about the latest in computer connectivity. Enjoy those blazing speeds!