Thunderbolt 4: Advantages and Disadvantages

This page explores the pros and cons of the Thunderbolt 4 interface.

Introduction:

The Thunderbolt interface has revolutionized how we connect laptops and desktops to high-performance storage, displays, and multimedia devices, all through a single cable. It leverages both PCIe and DisplayPort protocols and supports power delivery over the cable. It also allows daisy-chaining up to 6 devices. Different generations of Thunderbolt exist, including Thunderbolt 1, 2, 3, and the latest, Thunderbolt 4, each with varying speeds and features.

What is Thunderbolt 4?

Thunderbolt 4 is backward compatible with previous versions, delivering a robust 40 Gbps speed for transferring video, data, and power over a single cable.

Thunderbolt 4 has these requirements:

• One universal computer port
• Universal 40 Gb/s cables up to 2 meters in length.
• Supports two 4K displays (instead of just one) or a single 8K display.
• Accessories with four Thunderbolt ports
• Required PC charging on at least one computer port
• Required PC wake from sleep when connected to a Thunderbolt dock
• Thunderbolt networking (10 Gbps ethernet connection between PCs)
• Mandatory certification for all shipping computers, accessories, and cables
• Cable testing and cable quality audits for Thunderbolt cable manufacturers
• Required Intel VT-d based DMA protection

Benefits (Advantages) of Thunderbolt 4

Here are the advantages of Thunderbolt 4:

1. It supports docks with up to four Thunderbolt ports and universal cables up to 2 meters in length.
2. It’s compatible with the vast ecosystem of PCs and accessories that comply with Thunderbolt 3.
3. It offers increased performance compared to previous Thunderbolt versions.
4. It adheres to the USB4 Specification, transmitting data, video, and power through a single USB Type-C port at 40 Gbps.
5. It enables power savings by allowing users to wake their computers from sleep simply by touching a keyboard or mouse when connected to a dock.
6. Laptops with Thunderbolt 4 can accept input power up to 100 Watts and can supply 15 Watts externally.

Limitations (Disadvantages) of Thunderbolt 4

Here are the limitations of Thunderbolt 4:

1. It supports fewer devices in daisy-chaining (around 6) compared to USB (around 127) and Firewire (around 63).
2. Devices supporting Thunderbolt 4 tend to be more expensive than USB alternatives.
3. Laptop vendors must support Intel VT-d based DMA (direct memory access). VT-d is a security measure that protects the system by preventing DMA to pre-assigned domains. This can potentially create issues with manufacturers like AMD.

Conclusion

While Thunderbolt 4 shares the same speed as Thunderbolt 3, it offers numerous improvements and benefits over its predecessors.