Thunderbolt 4 vs USB4: A Detailed Technical Comparison

Thunderbolt 4 vs USB4: A Detailed Technical Comparison

In today's rapidly evolving technological landscape, data transfer and device connectivity technologies play an increasingly critical role. Among these, Thunderbolt 4 and USB4 stand out as cutting-edge solutions. They not only share a similar appearance but also support high-performance transmission and multifunctional connectivity. However, despite their apparent similarities, there are notable differences under the surface. This article provides an in-depth comparison of Thunderbolt 4 and USB4 in terms of performance, functionality, compatibility, and market adoption, helping readers make more informed purchasing decisions.

I. Overview

Origin of USB and Thunderbolt Technologies

1. USB Standard

USB, short for Universal Serial Bus, has been the dominant standard for wired connections between devices since its debut in 1998. From USB 1.0 to the latest USB4, each generation has seen improvements in speed and features.
USB4, in particular, is developed based on Thunderbolt 3 technology, offering high bandwidth and broad compatibility. It supports transfer speeds up to 40Gbps, video output, and up to 100W of PD fast charging.

2. Thunderbolt Standard

Thunderbolt is a high-speed interface technology developed by Intel in collaboration with Apple. It was first introduced in Mac products. Starting with Thunderbolt 3, the standard adopted the USB-C connector. Thunderbolt 3 supports 40Gbps speeds, high-resolution displays, and demanding peripherals such as external GPU docks.
Released in 2020, Thunderbolt 4 further improves functionality and performance, raising the minimum performance requirements and ensuring full backward compatibility with Thunderbolt 3.

II. Technical Comparison

1. Data Transfer Speed and Bandwidth

• USB4:
  USB4 has two main variants:

  • USB4 20Gbps (Gen 2x2)

  • USB4 40Gbps (Gen 3x2)
    The maximum theoretical transfer rates are 20Gbps and 40Gbps, respectively.

• Thunderbolt 4:
  Thunderbolt 4 also supports a maximum bandwidth of 40Gbps, but due to DisplayPort bandwidth reservations, the actual bandwidth available for pure data transfer is about 32Gbps.

2. Display Support and Peripherals

• USB4:
  Supports dual 4K 60Hz monitors or a single 5K 60Hz monitor.
  It allows dynamic bandwidth sharing between video and data and offers up to 100W fast charging. However, USB4 does not natively support external GPU docks.

• Thunderbolt 4:
  Supports dual 4K displays or a single 8K display, and supports external GPU docks, enabling enhanced device performance.
  It also supports daisy chaining and more extensive peripheral connectivity options.

3. Compatibility and Certification

• USB4:
  Built on Thunderbolt 3, USB4 is fully compatible with USB 3.2, 3.1, and 2.0 devices. However, actual performance varies depending on the manufacturer, and a lack of standardization can lead to inconsistencies.

• Thunderbolt 4:
  Offers comprehensive backward compatibility, supporting all previous Thunderbolt versions and USB standards. It undergoes rigorous Intel certification, ensuring high performance and reliability.

III. Real-World Applications and Market Impact

1. Market Adoption and Popularization

• USB4:
  As an open and royalty-free standard, USB4 has the advantage of low implementation cost, making it easier for manufacturers to adopt and helping it gain wide usage across devices.
  The lower cost of USB4 hardware and accessories supports broader consumer adoption.

• Thunderbolt 4:
  Despite its powerful features, higher implementation costs limit Thunderbolt 4 mostly to high-end laptops and devices.
  Its strict certification requirements slow down market adoption but ensure superior performance and security, making it ideal for users with demanding needs.

2. Peripheral and Accessory Market

• USB4:
  A wide range of compatible USB4 accessories, such as docks, cables, and external enclosures, are now available.
  Due to fierce competition, prices are dropping, giving users more affordable options and boosting market penetration.

• Thunderbolt 4:
  Accessories are more expensive due to higher technical requirements.
  However, its high-performance potential makes it attractive to advanced users. Devices like external GPU enclosures and high-speed storage units can perform at their best under Thunderbolt 4.

Conclusion

Thunderbolt 4 and USB4 are currently two of the most advanced data and display transmission technologies on the market.

• Thunderbolt 4 excels in comprehensive features and high performance.

• USB4 offers better value and accessibility for general users.

In the future, these technologies may continue to maintain their respective advantages while gradually converging through market-driven innovation, thereby improving overall user experience and system performance.

Ultimately, choosing between USB4 and Thunderbolt 4 should depend on your specific use case and budget. Understanding their technical differences and real-world applications will enable you to make a more informed and rational decision.