What is USB4?
USB4 is the latest generation of the USB specification, designed by the USB Promoter Group using Thunderbolt 3 technology as its foundation. It exclusively uses the USB-C connector and delivers data transfer speeds of up to 40 Gbps (USB4 Gen 3x2) or 80 Gbps (USB4 Version 2.0). Beyond raw speed, USB4 consolidates data transfer, DisplayPort video output, and USB PD power delivery into a single cable through an intelligent bandwidth-sharing mechanism, making it the most capable and versatile USB standard ever released.
In-Depth
Tunneling: One Cable, Multiple Protocols
The defining innovation of USB4 is tunneling, which allows data (USB), display (DisplayPort), and PCIe signals to travel simultaneously over one physical connection. Bandwidth is allocated dynamically: if you are only transferring files, the full bandwidth goes to data; if you plug in a monitor, the system carves out enough bandwidth for the display and gives the remainder to data. This eliminates the need for separate cables for video, data, and charging.
USB4 Version Comparison
| Version | Max Speed | Highlights |
|---|---|---|
| USB4 Gen 3x2 | 40 Gbps | Thunderbolt 3 compatible; baseline spec |
| USB4 Version 2.0 | 80 Gbps | Asymmetric mode enables up to 120 Gbps one-way |
| Thunderbolt 4 | 40 Gbps | USB4-compatible + Intel-certified quality |
| Thunderbolt 5 | 80 Gbps | USB4 v2.0 based + up to 120 Gbps |
USB4 Version 2.0 introduces an asymmetric mode that concentrates up to 120 Gbps of bandwidth in one direction, which is invaluable for external GPUs (eGPUs) and high-resolution multi-monitor setups that demand massive downstream throughput.
USB4 and Thunderbolt: The Relationship
Because USB4 is built on Thunderbolt 3, it is broadly compatible with Thunderbolt 3 and 4 devices. However, the USB4 specification makes Thunderbolt support optional for manufacturers, meaning not every USB4 port will recognize every Thunderbolt peripheral. If you need guaranteed Thunderbolt compatibility, choose a port or device that carries Intel’s official Thunderbolt 4 or 5 certification.
How to Choose
1. Determine Your Speed Requirements
For everyday external SSD file transfers, 40 Gbps (USB4 Gen 3x2) is more than sufficient. If you plan to connect an eGPU, drive 8K displays, or run multiple high-resolution monitors, USB4 Version 2.0 or Thunderbolt 5 at 80 Gbps is the better investment.
2. Verify Cable Ratings
A cable certified for 40 Gbps cannot achieve 80 Gbps, regardless of the port it is plugged into. Always match the cable’s certified speed to your needs. Shorter cables (0.8 m or less) are more reliable at peak speeds. Check manufacturer specifications rather than relying on appearance, since USB4 cables look identical to slower USB-C cables.
3. Confirm Peripheral Compatibility
USB4 ports are backward compatible with USB 3.x and USB 2.0 devices, but speeds will be limited to the device’s maximum. When building a USB4-centric setup, consider a USB4 docking station or hub that can distribute the bandwidth to multiple high-speed peripherals efficiently.
Recommended Products
USB4 accessories fall into two practical categories: hubs and docks that expand connectivity, and cables that unlock full 40 Gbps or 80 Gbps speeds. The picks below cover the most useful entry points for building a USB4-centric workstation. See our USB hub comparison for a broader look at docking options.
| Product | Highlights | Price Tier |
|---|---|---|
| Anker USB4 Multi-Port Adapter (4-in-1) | USB4 40 Gbps, 2×USB-C 10 Gbps, 2×USB-A 10 Gbps, bus-powered | Mid-range |
| CalDigit TS4 Thunderbolt 4 / USB4 Dock | 18-port, 98W laptop charging, dual 4K display, SD card | Premium |
| Anker USB4 Cable (0.8 m, 240W) | 40 Gbps certified, 240W EPR charging, USB4/TB3/TB4 compatible | Budget |
Anker USB4 Multi-Port Adapter — Best Compact USB4 Hub for Expanding Laptop Ports
The Anker USB4 Multi-Port Adapter is a palm-sized hub that turns a single USB4 or Thunderbolt 3/4 port into four high-speed connections: two USB4/USB-C ports at 10 Gbps each and two USB-A ports at 10 Gbps each. Bus-powered operation means no wall adapter needed — the hub draws power directly from the laptop’s USB4 port. Unlike passive USB-C hubs that throttle speed on older USB 3.x buses, the Anker USB4 hub negotiates a full 40 Gbps tunnel with compatible hosts, keeping all four ports genuinely fast simultaneously. For MacBook Air or Pro users who work from coffee shops and need to connect a USB-A peripheral, a secondary storage drive, and a display adapter without hunting for wall power, this compact hub is the low-friction answer.
CalDigit TS4 Thunderbolt 4 / USB4 Dock — Best Full-Featured Desktop USB4 Docking Station
The CalDigit TS4 is the reference-class desktop dock for professionals who need everything from one cable connection. Its 18 ports include five Thunderbolt 4/USB4 downstream ports, three USB-A 3.2 Gen 2 ports, SD and microSD card readers, 2.5 GbE ethernet, optical audio, and 3.5 mm audio in/out — all powered by a single cable connected to a USB4 or Thunderbolt 4 laptop. The host port delivers 98 W of laptop charging simultaneously, enough for a 14-inch MacBook Pro or Dell XPS 15 at full performance. Dual display support via Thunderbolt allows two 4K 60 Hz monitors from a single dock connection, critical for photo editing, software development, and data analysis workflows. CalDigit’s reputation for firmware stability and long-term macOS and Windows driver support differentiates the TS4 from cheaper alternatives that work at launch but develop compatibility issues with OS updates.
Anker USB4 Cable 240W — Best Certified USB4 Cable for 40 Gbps and 240W Charging
A USB4 cable is only as capable as its certification, and this Anker cable delivers the full specification: 40 Gbps data transfer, 240 W USB PD 3.1 EPR charging, and compatibility with USB4, Thunderbolt 3, and Thunderbolt 4 devices. The eMarker chip inside the connector communicates its 5 A / 48 V capability to the charger, enabling EPR charging profiles for gaming laptops and high-powered monitors. The 0.8 m length is the sweet spot for desk use — long enough to reach most configurations, short enough to avoid coil clutter. Critically, Anker includes a fold-flat plug design that survives repeated insertions better than thin consumer cables. This is the cable to buy when upgrading from an unverified USB-C cable that may be limiting your dock, display, or charger to 60 W or 20 Gbps when the hardware is capable of much more.
The Bottom Line
USB4 represents the convergence of data, video, and power into a single, high-speed standard. Whether you choose the 40 Gbps baseline or the 80 Gbps Version 2.0, USB4 future-proofs your connectivity for years to come. Match your speed tier to your actual use case, invest in properly rated cables, and confirm Thunderbolt compatibility if you rely on Thunderbolt peripherals. With USB4, one port and one cable can genuinely do it all.