What is Thunderbolt? (A Detailed Explaination)

Thunderbolt cable plugged into a laptop

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Thunderbolt is a hardware interface developed by Intel in collaboration with Apple that allows a single cable to carry multiple types of signals, such as USB, PCI, and Displayport.


Thunderbolt is also capable of carrying power and also allows you to charge your devices while also receiving and sending data. 


Currently, it’s quite popular in modern laptops as it allows you to connect high bandwidth devices such as fast NIC, multiple 4K displays, and high-speed storage with just one cable.


Evolution of Thunderbolt


In February 2011, Apple released the first few devices with Thunderbolt. These devices include the Macbook Pro 13, 15, and 17 inches. 


The first iteration of Thunderbolt used mini DisplayPort as its connector. It was capable of carrying a video signal via Display Port 1.1a. As for the data transfer rate, it can transfer data up to 20Gbps while also supporting 4 lanes of PCI 2.0.


Thunderbolt 2

Having the same mini Displayport, Intel announced the 2nd generation of Thunderbolt in June 2013. The same month Apple announced the first device with Thunderbolt 2, which was the Mac Pro 2013, which featured six Thunderbolt 3 ports.


The port was available on every Apple computer released in the following years until early 2015.


In terms of speed, Thunderbolt 2 was the same as the previous iteration. It updated the DisplayPort spec to 1.2, which allowed you to output to a single 4K monitor or dual Quad HD monitors.


At the same time, Thunderbolt 2 was backward compatible with Thunderbolt 1, which meant that you could use your old Thunderbolt 1 devices with your new computer.


Thunderbolt 3

Intel took a big leap in late 2015 when they released Thunderbolt 3. This time they bumped up the bandwidth to 40Gbps and implemented PCIe 3,0 with up to 4 lanes and the support of DisplayPort 1.4.


This meant that you had the ability to drive two 4K displays at the same time at 60Hz with one cable. Provided that the connector provided the full bandwidth to drive these displays.


 Or you could drive one 4K display at 120Hz or drive a single 5K display at 60Hz. Apple chose the latter and released a 5K display in collaboration with LG, named the LG Ultrafine 5K.


Another big change was the connector. Intel moved away from mini DisplayPort and shifted to USB C. This meant that along with Thunderbolt 3, it supported USB 3.2 10Gbps speeds.


Implementing USB C also brought USB power delivery, which meant that you could deliver up to 100W with a single USB C connector. This was ample to charge many notebooks at the time.


Thunderbolt 3 devices went on sale around the end of 2015, which included laptops from popular brands such as Dell, LG, MSI, Asus, Acer, etc.


Thunderbolt 4

The Thunderbolt 4 update was more of a Thunderbolt 3 minor refresh where they refined the overall Thunderbolt standard. 


Intel kept the bandwidth the same at 40Gbps. However, they made the minimum requirements for Thunderbolt more strict and precise.


Though on paper, Thunderbolt 3 supported 40Gbps, many manufacturers simply got away with a 16Gbps port that limited the capability of external devices such as high-speed storage and PCIe devices.


To address this issue, Intel raised the minimum requirements to 32Gb/s. This allowed for more proper support of something like dual 4K displays, which wasn’t implemented throughout the board with Thunderbolt 3.


Intel also required every device with Thunderbolt 4 to support USB C charging, support waking up from sleep via a Thunderbolt device. Intel further pushed the 40Gbps bandwidth support up to 2 meters. Cutting off the need to use active cables under 2 meters in length.


They also addressed some security vulnerabilities like Thunderspy, which helps make Thunderbolt more secure. Furthermore, Thunderbolt 4 was made to be also compatible with USB 4, which shares more or less the same features as Thunderbolt.


Thunderbolt 5

In Oct 2022, Intel previewed Thunderbolt 5, which aligns more with the USB 4 spec. The new standard supports 80Gb/s of total bandwidth and can go up to 120Gb/s when it comes to video-intensive use. 


This allowed Thunderbolt to support the newer DisplayPort 2.1 standards which can drive 8K displays up to 165Hz. Thunderbolt 5 also allows for double the PCIe data throughput than Thunderbolt 4, which helps connect newer graphic cards and storage devices.


As of writing this, the release date is not clear on the new standard. However, we hope to see new Thunderbolt devices in 2023.


What is a Thunderbolt port?

When it comes to modern Thunderbolt standards, such as Thunderbolt 3 and 4, it uses a USB C port. Older standards like Thunderbolt 1 and 2 used mini Displayport as their connector.


How fast is Thunderbolt’s data transfer rate?

As of writing this, the current Thunderbolt standard supports up to 40Gb/s. This is enough to drive high-resolution displays and connect fast storage.


How fast does a Thunderbolt cable charge?

Thunderbolt can deliver up to 100W of power, allowing you to charge ultrabooks with USB C. Though powerful devices such as a gaming laptop may require a powerful proprietary power adapter as it may require more than 100W. 


How to check if I have a Thunderbolt port?

Just check your device I/O and see if any of the USB C ports have a Thunderbolt port. If your device’s USB C port has a Thunderbolt port, it most likely supports Thunderbolt 3 or 4.


You can check your device specifications to see exactly what Thunderbolt standard it supports.


Do Thunderbolt cables work on any USB C port?

You can use Thunderbolt cables on any USB C port. However, you would only be able to use Thunderbolt features if the USB C port supports the Thunderbolt interface. 


If you plug a thunderbolt cable into a normal USB C port, then you will get the usual USB speed which is usually around 10Gbps. And if the USB C port supports DisplayPort, you can also get a video signal out of it.


What devices use Thunderbolt?

external GPU enclosure, external SSD, dock, and a monitor

You would usually find Thunderbolt on devices such as laptops and Desktop PCs. As for Thunderbolt-supported accessories, there are multiple accessories that you can buy. 

External GPUs

You can connect external GPUs to your computer via Thunderbolt. This comes in handy when you want to game at home with your laptop that does not have a great GPU but has a Thunderbolt port. 


You can check out something like the Razer Core X GPU enclosure to connect an external GPU to your laptop


However, do note that your GPUs won’t be able to work at their fullest due to the bottleneck caused by Thunderbolt bandwidth.


Thunderbolt Displays

You can connect Thunderbolt monitors to your computers. Apple has been at the forefront when using Thunderbolt for monitors. 


If you are connecting such a USB-C monitor to a laptop, it will not only get a video signal from the laptop, but it will also charge your laptop while also allowing you to connect other peripherals via a USB hub built into the monitor.


Something like the Samsung ViewFinity S8 27-inch monitor not only has multiple Type A port but also has a LAN port. This allows you to take full advantage of the Thunderbolt port.



Thunderbolt also allows you to connect fast external storage to your devices. You can connect something like the PHIXERO 2TB Portable SSD, which is insanely fast. You can edit videos from this drive, or you can play games without any hiccups.


Thunderbolt Docks

Thunderbolt docks allow you to connect multiple devices to something like a laptop with a single cable. 


This can come in handy when you want to use desktop peripherals like multiple monitors and external keyboards and speakers with your laptop, but you don’t want multiple cables sticking out of it.


Thunderbolt docks allow you to connect and disconnect multiple devices from your laptop with just one cable, avoiding the hassle of removing multiple cables and saving time.


You can get something like the Kensington Thunderbolt 4 dock, which allows you access to multiple high-speed ports such as a Gigabit Ethernet port, 10Gbps USB Type-A ports, etc.



Is Thunderbolt only available on Apple?

No, Thunderbolt is also available on non-Apple devices. There is no doubt that Apple has been on the forefront when it comes to promoting USB C and Thunderbolt. 


But you can find Thunderbolt on more devices, especially considering that Intel has made Thunderbolt royalty-free in order to promote it. 


Though we have to mention that it’s hard to find Thunderbolt on devices that are powered by AMD processors.


How do I add Thunderbolt to my laptop?

You can’t add Thunderbolt to your laptop. Thunderbolt is implemented at the hardware level, and you can’t additional high-speed ports to your laptop. 


However, you can add Thunderbolt to a desktop PC via a PCIe card.


You can plug something like the Gigabyte GC MAPLE RIDGE PCIe adapter into your desktop PC and get Thunderbolt connectivity on your PC.


Is Thunderbolt the same as HDMI?

No, Thunderbolt is not the same as HDMI. Thunderbolt can carry an HDMI signal, but that doesn’t mean you can use a Thunderbolt cable as a video cable and vice versa.


Is Thunderbolt backward compatible?

Thunderbolt 2 is backward compatible with Thunderbolt 1 as they share the same mini DisplayPort port. And Thunderbolt 4 and 5 are also backward compatible with Thunderbolt 3.


These devices would just slow down and operate at the older Thunderbolt speeds.


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