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USB4 is the new-generation USB standard that, if all goes to plan, will bring the flagging standard up to spec with some of its fastest competition, unify a number of confusing naming conventions under a single banner, and maintain use of the all-important reversible USB-C connector. Additionally, USB4 is likely to be the connector you use for almost everything over the next few years, from ever-faster data transfers, to outputting to ultra high definition external monitors, connecting older USB devices, and charging up your gadgets. Intel Corporation has significantly contributed to the development of USB4 technology, particularly through its work on the Thunderbolt protocol specification.
While it still faces stiff competition from the likes of Thunderbolt 4, USB4 is the hot new kid on the block, and it has all the potential in the world to dominate the next few years of wired connections. With the introduction of USB4 v2, the standard continues to evolve, promising even greater speeds and capabilities, with the potential to reach data transfer rates that surpass its predecessor.
What is USB4?
USB4 is, like USB 2.0, USB 3.0, and all the subsequent iterations, a USB specification developed and released by the USB Implementers Forum. USB4 is the latest iteration of the Universal Serial Bus (USB) protocol designed for high-speed data transfer. It builds on the strengths of USB 3.2 2x2 by maintaining the USB-C connection, but mandates a minimum throughput of 20 Gbps, and opens up the potential for double that. It also improves compatibility with Thunderbolt standards and ensures backwards compatibility with USB 3.x and USB 2.0, allowing tunnelling of DisplayPort and PCIExpress to better support higher resolution monitors over USB, and mandates USB Power Delivery.
It’s an altogether modern connector that will be more widely available than the competition, offer comparable features, and deliver exciting performance enhancements to anyone used to the older USB standards. The advent of USB4 v2 further enhances these capabilities, offering even faster data transfer speeds and improved power delivery, setting a new benchmark for USB performance.
It also brings the big quality of life improvement of starting from scratch with a single naming convention. USB4 cablesand devices have their specifications and that’s how they’ll remain, with no intention from the USB-IF of re-framing as it did with USB 3.0 as it morphed into 3.1, then 3.2 and its various generation designations.
The Benefits of USB4
USB4 has all the benefits of previous generations of USB ports, with a number of exciting additions that make it a great alternative to the likes of Thunderbolt 3 and Thunderbolt 4. The introduction of USB4 v2 promises to elevate these benefits even further, with enhancements that push the boundaries of what USB technology can achieve.
For raw bandwidth, USB4 mandates a minimum speed of 20 Gbps throughput. That’s technically only as fast as the best USB 3.2 Gen 2x2 ports, but that’s the floor with USB4, not the ceiling. It’s possible for devices built with USB4 to support up to 40 Gbps instead, with devices given specific logos on their packaging and ports, to show the maximum bandwidth available. With USB4 v2, these speeds are set to increase, providing users with even more impressive data transfer capabilities.
That 40 Gbps may not be guaranteed, but in devices that support it, it makes USB4 just as fast as Thunderbolt 3 and Thunderbolt 4, and one of the highest bandwidth solutions for transferring data at faster speeds.
That huge bandwidth also opens up support for higher resolutions using the DisplayPort Alt Mode 2.0 protocol. That gives it the ability to output to and display up to 8K resolution at up to 60Hz with HDR10 color, and provides high-quality audio transmission.
USB4 also supports DisplayPort 1.4 and PCI-Express tunneling, which lets it use smart bandwidth management to make the most of multi-use connections. For example, if you were using a USB4 connection to output to a 4K display, but also wanted to use that same connection for data transfer at the same time, the host system can allocate the maximum available bandwidth to the data transfer, without impeding the stream of 4K video. That’s more nuanced than the 50/50 split that more traditional DisplayPort Alt Mode allows, and should make for a more efficient and versatile connection than previous generations of USB.
USB4 enhances connectivity by allowing the transmission of video, audio, data, and power through a single cable.
All USB4 hosts and devices will have to support USB Power Delivery, too, making it possible to charge more capable devices like laptops and tablets over a USB4 connection. There’s no guarantee on the amount of power that will be provided by the device or host, but technically USB4 Power Delivery can be anything up to 100W, so some devices will be able to charge extremely quickly. The advancements in USB4 v2 are expected to further improve power delivery capabilities, making it an even more attractive option for high-performance devices.
USB4 was also designed from the ground up to be backward compatible with previous USB generations. That means it works with legacy USB 1 and USB 2 generation devices, leveraging dedicated wires within the USB-C connector to do so. However, as the USB-C connector was only implemented with later USB 3.1 devices, a USB-A to USB-C converter will need to be used for connecting older USB 1 and USB 2 devices over USB4. The same goes for any USB-A 3.0 or 3.1 devices, with USB-C 3.1 and 3.2 devices directly compatible with USB4 in all cases.
Thunderbolt 3 compatibility is also mandated for all USB4 hubs, although not all USB4 devices will support it. Conversely, Thunderbolt 4 devices must support USB4.
Of course, to take advantage of USB4 ports you’ll need USB4 cables that are up to the challenge. Cable Matters offers a wide range of USB4 cables and Thunderbolt 4 cables that also offer full compatibility with USB4.
USB-IF Certified 40Gbps USB4 Cable
Intel Certified Thunderbolt 4 USB4 40Gbps Cable
USB4 Ports & USB4 Specification
All USB4 ports and cables will use the type c connector. Older USB-A devices will be compatible through adapters and converter cables, however.
USB4 will fix the confusion around the naming convention, in that there won’t be devices with different names. Unfortunately, there will be USB4 devices that have different data transfer speeds available to them. This will be especially true of devices that haven’t been validated by the USB-IF, which will be a lot of them. Manufacturers can customize their products' performance and compatibility with existing technologies, highlighting the nuances of implementing capabilities across USB4 and Thunderbolt standards.
That said, major devices like laptops, tablets, and smartphones with USB4 support, are likely to adhere to the more typical specifications, with the most high-end of devices most likely to offer the greatest bandwidth for data transfers. USB4 comes in two versions: one supporting data transfer at 40 Gbps and the other at 20 Gbps. With USB4 v2, the landscape is set to change, as it introduces even faster speeds and more robust features, providing a glimpse into the future of USB technology.
The most basic of USB4 peripheral devices will offer 10 Gbps data transfer speed, with an official mode name of USB4 Gen 2x1. The lowest-spec USB-IF approved devices will have the USB4 20 Gbps moniker, and will have an appropriate label featuring the USB logo with a clear 20 next to it. It will officially use the USB4 Gen 2x2 mode to achieve that speed.
A small contingent of devices may use the USB 4 Gen 3x1 mode on a single lane, thereby delivering 20 Gbps of bandwidth, but without the USB4 20Gbps label of the USB-IF.
The most capable of devices will be come fitted with the USB4 40Gbps label – a USB logo with a 40 next to it – and will use USB4 Gen 3 x 2 to offer up to 40Gbps bandwidth with two lanes in each direction.
All hosts and hubs will have to offer DisplayPort tunnelling, and 20Gbps data transfer speeds, but they’ll be entirely optional for peripheral devices.
Data Transfer with USB4
When it comes to data transfer, USB4 sets a new benchmark with speeds of up to 40Gbps. This makes it ideal for transferring large files, streaming high-bandwidth content, and connecting multiple devices simultaneously. Whether you’re a professional dealing with large video files or a gamer looking for the fastest connection, USB4 has you covered. With USB4 v2 on the horizon, these capabilities are expected to expand even further, offering unprecedented data transfer speeds and efficiency.
The USB4 specification supports these impressive data transfer speeds while also allowing for dynamic sharing of a single high-speed data link between multiple devices. This means you can connect your laptop, desktop, and peripherals without compromising on speed or performance. The ability to dynamically share bandwidth ensures that each connected device gets the optimal data transfer rate it needs.
Backward compatibility is another key feature of USB4. It ensures seamless connectivity with previous versions of USB, so you don’t have to worry about your older devices becoming obsolete. The USB Implementers Forum (USB-IF) has also released new guidelines for branding and marketing to help consumers easily identify compatible products and cables. This makes it easier than ever to ensure you’re getting the highest performance from your USB4 connections.
DP Alt Mode
DisplayPort Alternate Mode (DP Alt Mode) is a powerful feature of the USB-C connector that allows it to carry DisplayPort signals. This means you can connect displays, projectors, and other devices that support DisplayPort directly through a USB-C port, simplifying your setup and reducing the number of cables you need.
The USB4 specification fully supports DP Alt Mode, enabling the connection of multiple displays and other devices. Whether you’re setting up a multi-monitor workstation or connecting to a high-resolution projector, DP Alt Mode ensures you get the best possible display quality. This feature is particularly useful for professionals who need to extend their desktop across multiple screens or present high-definition content.
DP Alt Mode is also backward compatible with previous versions of DisplayPort, ensuring seamless connectivity with older devices. The USB Implementers Forum (USB-IF) recommends using DP Alt Mode to connect displays and other devices that support DisplayPort, making it a versatile and future-proof solution for all your display needs.
USB4 vs USB 3: Backward Compatibility
USB4 makes major leaps over previous USB standards, raising both the floor and the ceiling potential over the older connector standard. Where 5Gbps transfer speeds were common on more affordable devices using USB 3.0, 3.1, or even 3.2 connections, USB4 will mandate an absolute minimum of 10Gbps, and most devices will support the USB-IF sanctioned USB4 20Gbps data rate. The key differences in performance and specifications between USB4 and USB 3 include these enhanced bandwidth capabilities and power supply requirements.
USB4 will also make exclusive use of USB-C cables, where USB 3 could be used with both USB-A and USB-C ports. That will make future compatibility far easier, and continue to encourage device manufacturers to use the reversible USB-C standard, which is much easier to use, as well as being both smaller, and more lightweight, making it easier to build more compact devices with USB4 support.
USB4 offers greater resolution support for external monitors – up to 8K at 60Hz on the most high-end devices. USB 3 can, at best, offer 4K support. More typically USB4 may offer 4K and 5K monitor support, but the higher resolution will certainly be possible on some devices.
USB4 will also raise the minimum port power for accessories to 7.5W, from 4.5W on USB 3. That will mean faster charging of compatible USB4 devices in general, although like USB 3.2, there will also be the option of up to 100W charging with USB Power Delivery, so some devices will charge far faster than others. Devices must be supported to meet these operational benchmarks.
USB4 and USB 2.0 Compatibility
One of the most user-friendly aspects of the USB4 specification is its backward compatibility with previous versions of USB, including USB 2.0. This means you can connect your USB4 devices to older USB 2.0 devices using adapters or hubs, ensuring seamless connectivity and making it easier to transition to the new standard.
The USB Implementers Forum (USB-IF) recommends using high-quality adapters and hubs to ensure optimal performance and reliability when connecting USB4 devices to USB 2.0 ports. This ensures that even older devices can benefit from the enhanced capabilities of USB4, such as faster data transfer speeds and improved power delivery.
The USB4 specification supports USB 2.0 speeds, ensuring compatibility with older devices without sacrificing performance. This backward compatibility is crucial for users who have a mix of new and old devices, as it allows them to connect their devices to older systems and peripherals without any issues. Whether you’re using a legacy device or the latest gadget, USB4 ensures you can connect and perform at your best.
USB4 Version 2: The latest USB4 standard
USB4 Version 2 is the latest advancement in the USB4 specification, setting a new benchmark for data transfer speeds and performance. Announced by the USB Implementers Forum (USB-IF), this update promises to deliver unprecedented capabilities, enhancing the already impressive features of USB4. According to the newly published USB4 Version 2.0 specification, data transfer rates can reach up to a staggering 80Gbps, and in some configurations, it can achieve up to 120Gbps using specialized USB-C cables.
This leap in speed is made possible by utilizing two lanes for data transfer in each direction, effectively doubling the bandwidth compared to the original USB4. This makes USB4 Version 2 ideal for high-performance applications, such as transferring large files, streaming ultra-high-definition video, and connecting multiple high-speed peripherals simultaneously. The enhanced capabilities of USB4 Version 2 ensure that users can enjoy faster, more efficient connections across a range of devices.
USB4 Version 2 also maintains backward compatibility with previous USB standards, ensuring seamless integration with existing devices and peripherals. This includes support for DisplayPort 2.1, allowing for even greater display resolutions and refresh rates, making it a perfect choice for gamers and professionals who require top-tier video output capabilities.
The introduction of USB4 Version 2 represents a significant step forward in USB technology, offering users a future-proof solution that caters to the demands of modern computing and connectivity. As manufacturers begin to adopt this new standard, we can expect to see a wave of new devices that leverage the full potential of USB4 Version 2, providing faster speeds, improved power delivery, and enhanced versatility.
The new Cable Matters USB4 V2 cable is a cutting-edge solution for high-performance connectivity. This USB-IF certified cable supports impressive data transfer speeds of up to 80Gbps, making it ideal for handling large files and high-bandwidth content. It also supports video resolutions up to 8K at 120Hz and 4K at 480Hz, ensuring stunning display quality for gaming and professional applications. Additionally, the cable offers up to 240W charging, providing efficient power delivery for a range of devices.
Is USB4 Worth it?
USB4 will almost always offer greater performance and features than any USB 3 hosts and devices. Like Thunderbolt 4, it is designed to raise the bare minimum of what USB is capable of, as well as offer some neat new features to improve the standard for use with modern devices.
Ultimately, USB4 is about unifying the USB standard around a new base specification of performance and features. It supports multiple data and display protocols, enhancing its capabilities compared to older versions. While there will be some difference between more affordable and high-end USB4 devices, it will be a standard that is far easier to understand than USB 3 and its various generations, and provide greater performance and features for anyone who uses it.
Its singular connector in USB-C, will make its use across a wide range of devices far simpler, even if they may not support the exact same speeds, and the increased scope for power delivery will enable fewer cables and chargers in user’s homes. Additionally, USB4 supports HDMI 2.1, enhancing display resolutions and refresh rates for high-performance gaming and video output capabilities.
Traditional USB Type A cables can only transmit data in one direction, but USB4 cables allow for data transmission in both directions simultaneously. This design also allows for a configuration where one direction can achieve significantly higher speeds compared to the other direction, indicating advancements in the USB protocol's efficiency. USB4 technology also enables PCIe connections, enhancing data transmission capabilities and supporting high-performance peripherals.
Users can transfer data at speeds reaching up to 80Gbps with USB4, surpassing previous USB versions. Information regarding advancements in USB technology can be found across various outlets. The advantages of USB4 in handling and transmitting high-bandwidth content, such as videos, make it a significant upgrade. The introduction of USB4 v2 is expected to push these capabilities even further, offering users an even more powerful and versatile connection standard.
USB4 is a long-awaited and much needed upgrade to USB 3, and though Thunderbolt 4 might still be the greater standard with its higher bar for entry, the lack of proprietary control over USB4 should give it far greater adoption across a wider array of devices.