What Is the Difference Between Thunderbolt 3 and 4? Clear Comparison

Shopping for a new laptop or dock and stuck wondering what is the difference between Thunderbolt 3 and 4? At first glance, they look nearly identical: both use the familiar USB-C connector, support up to 40 Gbps of bandwidth, and handle 4K displays. But under the hood, they follow different rules.

In this guide, we’ll break down how Thunderbolt 3 and 4 actually compare—speed, displays, charging, and more—so you can decide which one fits your workflow, gaming setup, or day-to-day needs.

What Is Thunderbolt?

Thunderbolt is Intel’s all-in-one wired connection standard that lets you move data, audio, video, and power through a single cable, meaning far fewer adapters and a lot less desk clutter.

It blends PCI Express for high-speed data with DisplayPort for crisp visuals, and can also deliver up to 100W of power. That means a single Thunderbolt port can run an external SSD, a 4K monitor, and charge your laptop—all at once, often through a docking station.

The tech first hit the market in 2011 as “Light Peak,” co-developed by Intel and Apple, before being rebranded as Thunderbolt. Thunderbolt 1 debuted at 10 Gbps, Thunderbolt 2 doubled that to 20 Gbps, and Thunderbolt 3 leapt to 40 Gbps, the same headline speed maintained in Thunderbolt 4.

Early 1 and 2 generations used Apple’s Mini DisplayPort plug, but starting with Thunderbolt 3 the interface moved to the more versatile USB-C connector you see on today’s laptops and docks.

Widely adopted across Apple devices and systems with Intel’s EVO platform, Thunderbolt has become a go-to solution for professionals, gamers, and content creators seeking to enhance productivity with fewer cables.

Key Differences Between Thunderbolt 3 and 4

So, what is the difference between Thunderbolt 3 and Thunderbolt 4, really? On paper, they look a lot alike. Both use the USB-C connector, support speeds up to 40 Gbps, and can handle 4K displays.

But the real difference is this: Thunderbolt 4 tightens the rules . Where Thunderbolt 3 could offer certain features, Thunderbolt 4 must, making it more reliable, more consistent, and just easier to work with.

Here’s a breakdown of what that means in practice:

Data Bandwidth & PCIe Performance

Both versions support up to 40 Gbps total bandwidth , but Thunderbolt 4 doubles the minimum PCIe data rate from 16 Gbps in Thunderbolt 3 to 32 Gbps . That bump makes a real difference if you’re using high-speed external NVMe drives, capture cards, or other data-hungry gear.

Display Support

Thunderbolt 3 only guarantees support for one 4K display at 60 Hz. Thunderbolt 4 requires support for two 4K displays or one 8K display, giving you more flexibility right out of the box, no special graphics card or fine print.

Cable Length & Convenience

With Thunderbolt 3, passive cables longer than 0.8 meters (about 2.6 feet) can drop down to just 20 Gbps unless you pay extra for active or optical cables. Thunderbolt 4 fixes that: certified passive cables up to 2 meters (6.6 feet) now maintain the full 40 Gbps speed, so you get more range without tradeoffs.

Charging Support

Thunderbolt 3 left laptop charging up to the manufacturer. Thunderbolt 4 changes that: at least one port on any Thunderbolt 4 laptop must support charging up to 100W. That makes it much easier to rely on a single cable for everything.

Security & Wake Features

Thunderbolt 4 builds in Intel VT-d DMA protection to guard against direct memory access attacks, and also supports waking your laptop from sleep via a connected keyboard or mouse through a dock. These were optional in Thunderbolt 3, but now they’re required.

Certification & Compatibility

Thunderbolt 4 devices go through a much stricter certification process than Thunderbolt 3, including full USB4 compatibility, cable validation, and a minimum of 15W power for connected accessories. With Thunderbolt 3, what you got depended heavily on the brand. With Thunderbolt 4, you know it all just works.

Side-by-Side Comparison

Conclusion: Which to Choose?

Now you know what the difference between Thunderbolt 3 and 4 is. While both move the same 40 Gbps in theory, Thunderbolt 4 raises the floor: locking in dual-4K (or single-8K) display support, 32 Gbps of PCIe bandwidth, 100 W laptop charging, and VT-d DMA security that Thunderbolt 3 never guaranteed.

If you’re still deciding between the two, it really comes down to how much flexibility and future-proofing you want.

Choose Thunderbolt 3 if:

• You’re using an older laptop or desktop that only supports Thunderbolt 3.
• You only need to connect a single 4K display and don’t plan to expand beyond that.
• You want to save money; Thunderbolt 3 docks and accessories are generally more affordable.
• You’re okay with variable support for features like laptop charging or wake-from-sleep, which aren’t required on TB3 devices.

For many everyday setups, especially if you’re not pushing multiple displays or high-performance storage, Thunderbolt 3 still gets the job done.

Opt for Thunderbolt 4 if:

• You want guaranteed support for two 4K displays or one 8K display right out of the box.
• You rely on fast external storage and want the higher 32 Gbps minimum PCIe throughput for smoother performance.
• You want a single cable to charge your laptop. Up to 100 W charging is required on all Thunderbolt 4 laptops.
• You need longer cable runs. Full 40 Gbps speeds are maintained on passive cables up to 2 meters.
• You care about built-in security features like Intel VT-d DMA protection.
• You want the convenience of waking your laptop from sleep using a docked keyboard or mouse.

And if you’re going the Thunderbolt 4 route, one dock stands out for sheer versatility is the Anker 778 Thunderbolt Docking Station (12-in-1, Thunderbolt 4).

One upstream Thunderbolt 4 port delivers up to 100W back to your laptop, while the downstream TB4 port, HDMI 2.1, and two DisplayPort ++ outputs let you drive a single 8K monitor or up to four 4K screens without juggling adapters.

You also get six USB ports—two USB-C (10 Gbps, 30W) and four USB-A—plus Gigabit-Ethernet, a Kensington NanoSaver lock slot, and a 180W power brick that keeps everything powered from one wall outlet.

If your workflow demands “plug once, forget it works,” the 778 checks every Thunderbolt 4 box and then some without crowding your desk with dongles.

FAQs

Can you plug Thunderbolt 3 into Thunderbolt 4?

Yes, Thunderbolt 4 is fully backward compatible with Thunderbolt 3. You can plug a Thunderbolt 3 device into a Thunderbolt 4 port, and it will function as expected. However, the connection will operate at Thunderbolt 3 speeds and capabilities, not Thunderbolt 4’s enhanced performance.

Is Thunderbolt 4 the same as USB-C?

Not exactly. While Thunderbolt 4 uses the USB-C connector, it’s a specific protocol that offers higher performance standards, including consistent 40 Gbps data transfer, support for dual 4K displays or a single 8K display, and enhanced security features. In contrast, USB-C refers to the connector type and can support various protocols with differing capabilities.

Is Thunderbolt 3 outdated?

No, Thunderbolt 3 is still widely used and remains a powerful interface, offering up to 40 Gbps data transfer speeds and support for high-resolution displays (4K@60Hz). While newer standards like Thunderbolt 4, USB4, and even Thunderbolt 5 have been introduced, many devices and accessories continue to utilize Thunderbolt 3, ensuring its relevance in today’s tech landscape.

Is Thunderbolt 4 worth it?

Thunderbolt 4 offers several enhancements over its predecessors, including mandatory support for dual 4K displays, consistent 40 Gbps data transfer speeds, improved security, and better compatibility with USB4. If you require high-speed data transfer, multiple high-resolution displays, and robust performance, investing in Thunderbolt 4 can be beneficial. However, for basic tasks, Thunderbolt 3 or USB-C might suffice.