What is Thunderbolt 3? Here’s everything you need to know

Peripheral cables are hard enough to keep track of without cutesy terms like “Thunderbolt” and nonsense names like “Type C.” Thunderbolt 3 — the newest version of Intel’s connection tech — may be incredibly confusing, having gone through several different phases since making the jump from Apple products to mainstream laptops and desktops.

Knowing the difference between these two technologies is essential, especially when you’re thinking about which computer is right for you. Don’t be surprised if you look at a new laptop and see nothing but USB-C and Thunderbolt advertised in the specifications. It’s the new norm.

What exactly is all this jargon? Let’s take a look.

The Thunderbolt 3 of today

Apple MacBook 13-inch Touch Pad
Bill Roberson/Digital Trends

Championed by Apple, Intel’s Thunderbolt technology has been around since 2009. However, by the time Thunderbolt 3 showed up in 2016, times had changed. USB-C had emerged as the newest USB connector, complemented by an updated and powerful USB cable that could provide up to 15 watts of power for devices (far more than older standards) and up to 100 watts for charging compatible laptops or similar devices. It was a considerable change for both USB and the future of many standard computer connections.

In response, Thunderbolt’s architects made a brilliant decision: Rather than face-off against USB-C, they joined it. Thunderbolt 3 ditched the old Mini DisplayPort connector and switched to a USB-C connector, combining the two technologies into one particularly-robust hybrid.

The move to USB-C allowed Thunderbolt 3 to expand from Apple devices to other PCs and laptops, which is ongoing but finally possible. The only downside was the issue of compatibility — Thunderbolt 3’s new USB-C connection isn’t compatible with devices based on Thunderbolt or Thunderbolt 2 without an expensive adapter.

Here are some things you can do with a Thunderbolt 3 port today:

  • Transmit data at a rate of up to 40Gbps, depending on the configuration.
  • Output video to two 4K monitors at 60Hz.
  • Charge smartphones and most laptops with up to 100 watts of power.
  • Connect to an external GPU, depending on the configuration.

If you’re wondering whether or not your USB-C port supports Thunderbolt 3, look for the little lightning bolt symbol next to the opening, which often differentiates it from a standard USB-C port.

The history of Thunderbolt technology

thunderbolt-cables

Thunderbolt technology originally began in the late 2000s as an Intel project called Light Peak, which was intended to add optical data transfer to traditional data transfer used with computer peripherals (principally, combining wire and fiber optics). Engineers soon found that their prototypes with standard copper wiring were already achieving the results Intel wanted but at a much lower cost.

This new product was then released as Thunderbolt in the early 2010s and at first available only on Apple devices, designed to be a potent and flexible connection. Compared to the (often brand-specific) cables floating around back then, this was an impressive creation suitable for many purposes. It was particularly promising for designers or engineers who were using laptops but still needed high-powered connections to external storage, high-resolution displays, and similar accessories.

Since the first Thunderbolt release made it out the door with some help from Apple, it was only available for Macs for the first year or so. In addition to limited availability, this new tech required unique Thunderbolt cables, and they tended to be expensive — around $50 or so.

Dan Baker/Digital Trends

Technology marched on. Time had provided a more accurate look at how Thunderbolt was being used and where it should head in the future.

The arrival of Thunderbolt 2 in June 2013 brought several significant changes to Thunderbolt technology. For one, it enabled simultaneous file data and video data transfers — what Intel called “a lot of eye-popping video and data capability.” This achievement was accomplished by combining the two 10Gbps bi-directional channels of the first-generation cable to create a single 20Gbps bi-directional channel. While the overall bandwidth didn’t change, these second-generation cables quickly showed better performance than any other popular peripheral cable of the day.

Another significant change was compatibility with the latest DisplayPort standards and 4K. While still a little ahead of its time, 4K resolution was on the horizon. Users who depended on Thunderbolt connections were glad to know that the highest solutions would be supported when necessary.

Also, crucially for users, Thunderbolt 2 devices worked with the original Thunderbolt-compatible devices, even if you wanted to mix and match different generations. Again, Thunderbolt would remain an Apple exclusive using the Mini DisplayPort connector until the following generation.

The Thunderbolt 3 standard was announced in June of 2015 and immediately declared “a match made in heaven.” Devices supporting Thunderbolt 3 through the USB-C connector followed in December. Recently, devices with Thunderbolt 4 ports have been released at CES, promising doubled minimum data and video requirements. They’re also capable of supporting one 8K monitor or two 4K monitors and a PCI Express rate of 32Gbps.

The latest Thunderbolt developments

Dell Thunderbolt Dock TB16
Bill Roberson/Digital Trends

Just as the original Thunderbolt and Thunderbolt 2 have gone out of fashion, the updates to Thunderbolt 3 and 4 will continue. Charging devices using USB-C connections has become more common, and compatibility has pressed onward to include the latest USB 3.2 cable standard. However, this is still a work in progress, so always double-check your cables.

The Thunderbolt may lose its top spot as the fastest connection with new tech like the USB4 standard coming into the conversation. Official data says that the USB4 is similar to the Thunderbolt with fast transfer speeds up to 40Gbps. The recent standard USB 3.2 Gen2 delivers 10Gbps. Thunderbolt seems pressured to keep up. However, the Thunderbolt 3 has more than high-speed data to offer users – its dual-protocol offers a plethora of video bandwidth.

Transferring data at high speeds has security threats. A Thunderclap vulnerability relates to Direct Memory Access (DMA) rights with USB-C, FireWire, and Thunderbolt. Like PCI Express add-ins, malicious threats can bypass security and let hackers run codes and steal data. 

Most Mac products work with the Thunderbolt 3, including compatibility with the Mac Mini and MacBook Pro, and Air. Each comes with Thunderbolt 3 ports that increase virus risk. When utilizing your Thunderbolt 3 port, continue using trusted devices and do not try it with a device you have never used. Use your judgement. 

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