The future of the USB standard

The USB standard has been around since 1996. Its initial format, USB 1.0, was succeeded by 2.0, then the more confusing USB 3.0/3.1/3.2 versions. Thankfully USB4 is the (simpler) name of the latest open USB standard based on Thunderbolt 3 technology. USB4 supports up to 40Gbps bandwidth (depending on implementation), and includes optional support for DisplayPort, PCIe tunnelling and host-to-host communication.

Basic USB4 host implementations typically support 20Gbps, and accessories receive only 7.5W of power, compared to Thunderbolt 4’s 15W. USB4 is royalty free and governed by the USB Implementers Forum (USB-IF), making it more common in mid-range and budget devices. While USB4 Version 2.0 boosts the maximum bandwidth to 80Gbps, it is still rolling out as of 2025 and is not yet widespread.

Several key designs of USB4 include:

• Display, data and load/store functionality with the use of a single USB-C connector (and only USB-C)
• Universally compatible with existing USB and Thunderbolt products
• Defined port capabilities for a predictable and consistent user experience
• Increased host flexibility to configure bandwidth, power management and other performance-related parameters for system needs

Same but different

Although USB4 was created based on Thunderbolt technology, there are quite a few notable differences. Thunderbolt is a high-speed port technology developed by Intel and Apple in 2011. Since its debut, it has evolved significantly. Thunderbolt 4, released in 2020, improved data transfer, video output and power delivery standards over Thunderbolt 3. In late 2023, Intel announced Thunderbolt 5, offering even greater bandwidth and performance. Today, Thunderbolt 4 is widely adopted, and Thunderbolt 5 is beginning to appear in high-end devices.

Thunderbolt 4 supports USB4 and PCIe Gen 3 and boasts a consistent 40Gbps bandwidth across all certified cables, mandated DMA protection to improve security against cyberattacks like memory snooping and up to 100W USB power delivery for charging laptops (accessories get a minimum of 15W). With its DisplayPort 1.4 support, it can connect dual 4K displays.

Thunderbolt 5 offers everything its predecessor does, with significant improvements in speed (80Gbps), power delivery (140-240W) and support for PCIe 4. You can connect as many as three 4K displays via a single cable with its incorporation of DisplayPort 2.1, leapfrogging Thunderbolt 4. Like previous versions, Thunderbolt 5 uses the USB-C connector and is backwards compatible with Thunderbolt 3, Thunderbolt 4 and USB4. As of mid-2025, it is available on selected high-end laptops and desktops, especially those using Intel’s Meteor Lake or newer platforms.

USB4 is an open standard and enjoys broad support from basically every manufacturer out there, as well as contemporary operating systems, so compatibility is not an issue. Many new laptops support USB4, but not all use it to its full capacity, or offer Thunderbolt compatibility. Knowing which port standard you should go for depends on what you want for your system. If you’re planning on using two or even three high-res monitors, the guaranteed DisplayPort support of Thunderbolt 4 and 5 puts them ahead. If you don’t think you’ll be using that many accessories, particularly external storage drives, the lower data transfer rate and power supply of USB4 may matter less to you. Ultimately, you’ll need to choose based on your priorities.