External GPU Enclosures: USB 3.1 or USB-C vs. Thunderbolt 3

Introduction

When it comes to external GPU (eGPU) enclosures, many users wonder if it's possible to connect them to their laptops via USB 3.1 or USB-C rather than the commonly used Thunderbolt 3. In this article, we will explore the differences between these connection options, their performance impacts, and when it might be suitable to use USB 3.1 or USB-C.

Key Points

Performance

Thunderbolt 3 offers significantly higher bandwidth, up to 40 Gbps, compared to USB 3.1 (up to 10 Gbps) and USB-C, which can vary depending on the standard being used. This difference in bandwidth translates to meaningful differences in performance, especially for gaming and graphics-intensive tasks. USB 3.1 or USB-C connected eGPUs may struggle to provide the same level of performance as those connected via Thunderbolt 3.

Compatibility

While some eGPUs are designed to work with USB-C connections, their performance may not match those connected via Thunderbolt. The performance bottleneck can limit the capabilities of the GPU, particularly in demanding applications. It's important to check the specific model and its compatibility before using an eGPU.

Availability

There are a few eGPU enclosures that specifically advertise USB-C compatibility, but they are less common compared to Thunderbolt 3 options. These enclosures may also not support high-end GPUs or deliver the same level of performance.

Use Cases

If your laptop supports only USB 3.1 or USB-C (without Thunderbolt), you might still be able to use an eGPU, but it's crucial to verify the specific models and their compatibility. The eGPU might be more suitable for less demanding tasks or casual gaming rather than high-performance gaming or professional graphics work.

Throughput and Latency

USB 3.1 or 3.0, or even 3.1 gen 1 and 3.2 gen 1, has throughput that is significantly lower than Thunderbolt 3. A full Thunderbolt 3 connection is equivalent to a PCIe 3.0 x4 interface, offering a throughput of 40 Gbps. In contrast, USB 3.1 3.2 gen 1 has a throughput of 5 Gbps, while USB 3.2 gen 2 can reach up to 10 Gbps. These throughput differences can impact the performance of the GPU, potentially leading to lag and lower frame rates.

Latency is another critical factor. USB 3 can have latencies ranging from 128 microseconds to around 30 microseconds, depending on the connection type. Thunderbolt 3 has latencies that range from 300 nanoseconds (0.3 microseconds) to 1 microsecond. These latency differences can also affect the performance of the GPU, as lower latency typically results in smoother and more responsive gameplay.

Theoretical DIY Options

While USB 3.1 or USB-C may not be sufficient for high-performance tasks, it's theoretically possible to create a Thunderbolt-like connection using M.2 slots within the laptop. However, this would require a do-it-yourself approach and might result in a less aesthetically pleasing setup. Furthermore, this method is not officially supported and comes with potential risks and compatibility issues.

Conclusion

While it's indeed possible to use USB 3.1 or USB-C for eGPU enclosures, Thunderbolt 3 is still the preferred connection standard for optimal performance. When considering an eGPU setup, it's essential to check the specifications and performance reviews of any enclosure to ensure it meets your needs. Always prioritize Thunderbolt 3 for the best and most reliable experience.