What’s the Difference Between USB 3.1 and USB 3.0, and What Are the Advantages of USB 3.1?

            What’s the Difference Between USB 3.1 and USB 3.0?

According to test results, the actual performance of the USB 3.1 interface is significantly higher than that of USB 3.0. USB 3.1 delivers sequential read/write speeds of around 500MB/s to 600MB/s, with peak performance even exceeding 700MB/s. In comparison, USB 3.0 interfaces typically offer sequential read/write speeds between 300MB/s and 400MB/s.

Although the theoretical bandwidth of USB 3.1 is rated at 10Gbps, part of this bandwidth is reserved for supporting other functions. As a result, the actual effective bandwidth is around 7.2Gbps, which translates to a theoretical maximum transfer speed of approximately 900MB/s. This suggests that there’s still room for improvement in USB 3.1 performance, and speeds of at least 800MB/s should be achievable.

USB 3.1 has become a hot topic of discussion. As the latest USB specification launched by major companies, including Intel, USB 3.1 significantly increases data transfer speeds, reaching up to 10Gbps. Compared to USB 3.0, this new standard adopts a more efficient data encoding system, offering more than double the effective data throughput. It remains fully backward-compatible with existing USB connectors and cables.

USB 3.1 products have gradually entered the market, especially in motherboards that provide expansion interfaces for traditional host devices. Although Intel's upcoming 100-series chipsets won’t offer native USB 3.1 support, just like USB 3.0 in the past, third-party controller chips are currently used to enable the new interface.

Released in July 2013, the USB 3.1 standard doubled the theoretical maximum bandwidth of USB 3.0, reaching 10Gbps (SuperSpeed+). It also replaced the previous 8b/10b encoding system with a more efficient 128b/132b encoding, reducing bandwidth loss from 20% to just around 3%. This change brings the theoretical bandwidth to over 1.2GB/s, meaning that in real-world applications, USB 3.1 transfer speeds could approach 1GB/s.

In addition to offering higher speeds and fixing issues from earlier versions, USB 3.1 also introduced the Type-C connector, which has drawn even more attention. Similar to Apple’s Lightning connector, the Type-C connector removes the traditional keyed design, allowing it to be plugged in either way, greatly improving usability.

Another major selling point of USB 3.1 Type-C is its enhanced charging capability. Under the USB 3.1 standard, power delivery has been significantly increased to 20V/5A (up to 100W, limited to Type-A/B), while Type-C supports up to 12V/3A (36W), which is sufficient for many ultrabooks. This is one reason why Apple’s New MacBook replaced the MagSafe connector with Type-C for charging. Functionally, USB 3.1 Type-C also introduces Alternate Mode, allowing the Type-C interface and cables to transmit non-USB data signals. Currently, Alt Mode supports DisplayPort 1.3 and MHL 3.2, and USB-IF is exploring support for more standards like Ethernet.

USB 3.1 vs USB 3.0 Transfer Speeds

Even though native USB 3.1 support is not yet widespread, third-party USB 3.1 solutions can outperform native USB 3.0 implementations by up to 60% in peak read/write speeds, demonstrating promising overall performance.

Summary of USB 3.1 Advantages

1. Extremely High Bandwidth & Fast Transfer Speeds
   With a theoretical bandwidth of 10Gbps, USB 3.1 can achieve actual read/write speeds of up to 800MB/s in real-world scenarios.

2. Ultra-thin Connector Driving a New Wave of Ultra-slim Devices
   The traditional USB connector measures 1.4cm long and 0.65cm wide, no longer suitable for modern ultra-thin devices. The USB 3.1 Type-C connector is only 0.83cm long and 0.26cm wide, making it better suited for slim devices. Just as Mini USB and Micro USB helped kick off earlier waves of thinner smartphones, USB 3.1 Type-C is expected to spark a new round of ultra-thin device development.

3. Reversible Plug Design Greatly Improves User Experience
   The Type-C connector’s reversible design solves the long-standing frustration of USB plug orientation. Android users in particular will appreciate finally being able to plug in their devices correctly without looking.

4. Higher Power Output
   Compared to USB 2.0’s 5V/0.5A and USB 3.0’s 5V/0.9A, USB 3.1 allows for up to 20V/5A power delivery (100W), enabling it to power or charge even power-hungry devices like laptops.

5. More Versatile Interface Functionality
   With support for Alternate Mode, the USB 3.1 Type-C interface can carry not only USB signals but also video and other data protocols like DisplayPort, MHL, and Ethernet, making it a true multi-functional connector.