What is Thunderbolt and How It Works? [Here’s the Answer]

Apple reported massive record-breaking earnings in the fourth quarter of 2020, a record $9 billion in revenue, which pushed Apple to have earned an astounding $28.9 billion in revenue for 2020! The latest M1 MacBook Air and Pro are to thank for their high sales. These notebooks brought lots of innovation and significant port upgrades compared to their predecessors.

The two ports come with Thunderbolt ready technology, and with the latest Thunderbolt 4 release, we are hoping that Apple incorporates it into their future MacBook line. So, what is the Thunderbolt interface?

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What Is the Thunderbolt?

As with all technology, Thunderbolt has quickly evolved throughout the years. We will discuss each version of the Thunderbolt later on, but we will explain it in general for now. The Thunderbolt supports high-resolution displays and high-performance data within one port, and its connectivity allows you to combine different devices to your computer through a daisy chain of cables.

In simple terms, Thunderbolt combines audio, data, power, and video into one connection. One of the most meaningful advantages is that Thunderbolt’s underlying technology made the concept of a USB-C hub possible since it can transfer up to 100W of power. Using the MacBook Thunderbolt port and a USB-C hub can provide the user with various ports, including HDMI video output, Ethernet, USB 3.0, and an SD & TF card input.

Development History of the Thunderbolt

Conceived initially as Light Peak, Intel sought to improve existing computer ports with this technology. Intel described the technology as having a primary speed of 10Gbps over plastic optical cables and promising a final rate of 100Gbps. In 2009, at IDF (Intel Developer Forum), Jason Ziller, head of Intel’s Optical I/O Program, announced Light Peak technology.

Intel originally intended it to run exclusively on fiber cabling using optical components and flexible cabling, but it proved to be too costly to produce. Intel shifted to electrical connections to reduce costs and supply 100W of power to connected devices, which proved to be the best decision they made as it enables the use of USB-C hubs, as previously mentioned.

In 2011, Apple joined the development of the Light Peak concept. Soon after, Apple registered Thunderbolt as a trademark, removing the Light Peak name. Later, Apple transferred the trademark to Intel, which now holds dominant intellectual-property rights. Ever since Apple bought the right to use Thunderbolt, they have made the necessary port upgrades to all of its devices.

Apple and Thunderbolt

Before the reign of the Thunderbolt, Apple and a few other companies (Sony and Panasonic) developed Firewire, which was able to run laps around USB 1.0 technology. Of course, Apple being an innovative company, continued to use Firewire and improve it throughout the years. Until the release of USB 3.0, which proved to be a lot better than Firewire technology.

That’s when Apple decided to look for an alternative to Firewire that could compete with USB 3.0. Fortunately, Intel had been developing Thunderbolt 1 (formerly known as Light Peak), which could directly challenge USB 3.0 technology. Apple bought the property right to use Thunderbolt and quickly made port upgrades to their devices to Thunderbolt 1.

Since 2011, Apple has used Thunderbolt on all of its MacBooks. They are so confident about Thunderbolt tech that all of the new MacBooks only have it as ports. While their iPhones don’t carry Thunderbolt capability, they still use Lighting ports, and even then, they are slowly switching to MagSafe technology. Now let’s break down the different versions of Thunderbolt so you can see how much it has improved.

Thunderbolt 1

Intel, alongside Apple, planned to release the Thunderbolt 1 in early 2011, using it on MacBooks. Unfortunately, the USB Implementers Forum announced that the USB port was not open to modification to accept the Thunderbolt. This led Intel and Apple to use the Mini DisplayPort connector instead of the USB connector.

The main features were:

Two data transfer channels – each supporting 10 Gbps (total 20 Gbps)
Protocol 4 x PCI express 2.0
DisplayPort 1.1a capability

Despite most computer ports being USB only at the time, Intel and Apple proved to the world that Thunderbolt technology was about to overtake USB 3.0.

Thunderbolt 2

Two years after (2013) the release of Thunderbolt 1, Intel announced Thunderbolt 2. While its data transfer capacity remained the same (20 Gbps), Intel significantly improved its video output capacity. It supported video streaming to a single 4K video monitor, quite the improvement! Unfortunately, the USB-IF (USB Implementers Forum) refused to make it into a USB connector type, meaning that Intel would use the Mini DisplayPort connector again.

The main features were:

A combined data transfer channel supporting 20 Gbps
Protocol 4 x PCI express 2.0
DisplayPort 1.2 capacity

Interestingly, ASUS was the first to launch a product with Thunderbolt 2 capability. Apple later released the MacBook Pro with Thunderbolt 2 in late 2013.

Thunderbolt 3

The USB-IF continued to make port upgrades to existing USB ports in order to compete with the Thunderbolt. Thankfully though, the USB-IF and Intel agreed, and the Thunderbolt series could finally use USB connectors. Intel began to design the Thunderbolt 3 to be compatible with the USB-C connectors, which is the most common USB connector.

The Thunderbolt 3 took two years to develop, and several manufacturers officially released it in late 2015. Apple didn’t release the Thunderbolt 3 to their product line until late 2016 with the MacBook Pro models. It proved to be superior to the Thunderbolt 1 and 2 in every way.

It doubled the previous data transfer capacity, improved video output, and introduced something unexpected, power charging capability!

The main features are:

A data transfer channel supporting 40Gbps
Protocol 4 x PCI express 3.0
DisplayPort 1.2
HDMI-2
USB Power Delivery of 100w

In an effort to make Thunderbolt 3 the future standard in all devices, Intel made Thunderbolt 3 royalty-free in 2017. The USB-IF took advantage of this and began to develop USB4, their own Thunderbolt 3 variant. A few years later, Intel announced Thunderbolt 4.

Thunderbolt 4

Intel has continued to improve its port upgrades, and in 2020 they announced the Thunderbolt 4. While the Thunderbolt 4 remains similar to the Thunderbolt 3, it still has some minor differences. The main difference comes in video output capacity, as the Thunderbolt 4 can support dual 4K displays.

The main features are:

A data transfer channel supporting 40Gbps
Protocol 4 x PCI express 3.0
DisplayPort 1.4
USB4 Compatibility
Backward compatibility with Thunderbolt 3
Intel VT-d based DMA protection

It has power charging, so you can still use a USB-C hub or docking station to power your other devices. Let’s look into a little more detail on some of the features.

External Monitors

You can connect multiple displays at once. One Thunderbolt 4 port can connect up to two 4K 60Hz DisplayPort or HDMI monitors using a hub or dock.

SecurityVT-d based DMA protection helps prevent security threats by remapping inquiries from external devices and monitoring for proper permissions.

PCI Express

If you like to live-stream, Thunderbolt 4 has you covered as you can utilize a PCIe expansion to access compatible PCIe devices. Likewise, you can use an external SSD to run applications or games without latency.

Data Transfer Capability

The Thunderbolt 4 has bidirectional data transfer bandwidth. With a speed of 40Gbps, you’ll be able to transfer things from one device to another in seconds!

As you can see, there are several distinctions between Thunderbolt 3 and 4. With the Thunderbolt 3 being royalty-free, it will continue to be the standard in current and future devices.

After seeing the development history of Thunderbolt, you may wonder if USB-C is the same as Thunderbolt 3 or 4. After all, they use the same connector. Though true, they are still different but let’s answer that question briefly in the next section.

Is Thunderbolt the same as USB-C?

Thunderbolt 3 has the capacities of USB-C, but USB-C does not have the capabilities of Thunderbolt 3. The Thunderbolt 3 port has the same shape as the USB-C port, as we already know. However, if you were to plug a Thunderbolt 3 cable into a USB-C port, you would have limitations on capabilities.

Thunderbolt 3 has more extraordinary performance when it comes to speed and video presentation. Its speed allows for swifter access to more data when compared to USB-C. Thunderbolt 3 works at a native speed of 40Gbps while USB-C operates at 10 Gbps.

Thunderbolt 3 can present video content on two 4K displays when it comes to the video display. In comparison, USB-C can display one 4K video display. Because of this, the USB-IF (USB Implementers Forum) has been working on the next-gen USB system, the USB4.

Does that mean the Thunderbolt 4 will lose its innovative edge? Let’s briefly discuss the difference between USB4 and Thunderbolt 4.

Difference Between USB4 and Thunderbolt 4

The USB4 spec is based on the Thunderbolt 3 protocol specification. Since Thunderbolt 4 is backward compatible with Thunderbolt 3, it means someone who has a USB4 ready-port on their laptop can use a Thunderbolt 4 device. So what is the main difference?

The difference is that the USB4 starts at 20Gbps and can reach 40 Gbps, unlike the Thunderbolt 4 that begins at 40Gbps. Also, USB4 is royalty-free, so that manufacturers can make USB hubs or docking stations freely. The bottom line is that not all USB 4 devices will be as powerful as certified Thunderbolt 4 ones, but it will come close.

To Sum Up

Hopefully, we answered the question, “What is Thunderbolt?” and you have a more thorough understanding of Thunderbolt technology. As you can see, Intel has considerably improved the world of ports with the Thunderbolt. We should expect Thunderbolt to become the future of all port upgrades, so better to start understanding it now!