Microsoft belatedly attempts to tame USB-C confusion with its rules for PC OEMs

Recent insights from Windows Diagnostics Data reveal a notable challenge within the PC ecosystem: 27 percent of computers equipped with USB4 are experiencing limited functionality notifications. This occurs when users connect a USB-C device that requires specific features—such as alternate mode—that are not supported by the PC. As articulated by Microsoft Senior Product Manager Ugan Sivagnanenthirarajah, the issue does not lie with the reversible USB Type-C connector itself, but rather with the inconsistent implementations of USB-C port capabilities across various devices.

Microsoft’s baseline requirements for USB-C and USB4 ports on Windows PCs.
Credit: Microsoft

Microsoft has established foundational requirements for USB-C ports, mandating that they include essential features such as “PC charging support” and the capability to connect at least one external display. Additionally, these ports must be able to supply a minimum of 4.5 watts of power to connected accessories. While Microsoft does not enforce higher transfer speeds—ranging from 10 to 80Gbps—or specific USB-PD wattage levels, it does set a baseline expectation for users: any USB-C port on a Windows laptop from major OEMs should at least deliver USB 3.x speeds, display output, and charging support.

In the realm of Thunderbolt technology, Intel continues to oversee certification for its specifications. Thunderbolt 4 and 5 ports encompass a comprehensive suite of USB-C capabilities, including support for PCI Express devices, high transfer speeds of 40 or 80Gbps, and the ability to connect multiple external 4K displays while providing up to 15 watts of power for accessories. Notably, any ports that claim 40 or 80Gbps USB4 support are also required to be compatible with Thunderbolt 3-certified accessories.

Herding cats

The Windows Hardware Compatibility Program (WHCP) plays a crucial role in addressing these challenges by offering automated testing tools for PC manufacturers. This initiative ensures that new systems operate seamlessly with Windows, while also enabling Microsoft to gather data that aids in identifying and resolving issues across the broader Windows ecosystem. A significant aspect of the WHCP requirements is the stipulation that USB-C ports utilize Windows’ built-in USB drivers. This approach allows for streamlined distribution of fixes through Windows Update, minimizing the need for additional intervention from PC builders.

Winsage
Microsoft belatedly attempts to tame USB-C confusion with its rules for PC OEMs