Mac Tips

Thunderbolt 4 & 3 Explained

Everything you need to know about Thunderbolt 4 and Thunderbolt 3.

Up to 40GbpsFast data transfer

Dual 4K / 8KDisplay support

Up to 100WPower delivery

UniversalUSB-C compatible

Thunderbolt 4 and Thunderbolt 3 are the connectivity standards behind most of the docks, displays and fast storage used with modern Macs. They look identical (both use USB-C) and share the same headline speed — so what's the difference, and which do you need? Here's a simple guide.

Thunderbolt 3

Thunderbolt 3 introduced the now-familiar USB-C connector and up to 40Gbps of bandwidth over a single cable — carrying data, video and power together. It's been the backbone of Mac docks for years and remains a reliable, great-value choice for most setups: a display, external drives, ethernet, and charging your laptop, all through one cable.

Thunderbolt 4

Thunderbolt 4 keeps the same 40Gbps top speed but raises the minimum guaranteed capabilities, so you always know what you're getting:

• Drive two 4K displays or a single 8K display (Thunderbolt 3 only guaranteed one display).
• Double the minimum PCIe data rate (32Gbps) for faster external storage.
• Support for longer cables at full speed.
• Wake-from-sleep with a connected keyboard/mouse, plus stronger anti-tampering security.

In short: Thunderbolt 4 is the dependable all-rounder for modern Macs, with guaranteed dual-display and power delivery.

Thunderbolt vs USB-C vs USB4

This is where it gets confusing — they all share the USB-C shape. The connector is the same, but the capability behind it differs:

• USB-C is just the connector. Speed and features vary widely.
• USB4 can reach 40Gbps and overlaps heavily with Thunderbolt, but display and PCIe support aren't always guaranteed.
• Thunderbolt 4 guarantees the full feature set every time.

Which should you choose?

For most people, a Thunderbolt 4 dock is the sweet spot — guaranteed dual displays, fast storage and future-friendly. If you're on a budget or only need a single display, a Thunderbolt 3 dock still delivers excellent value. Either way, make sure your Mac's port and your cable match the dock to get full speed.