A user reports that their PC's USB 3.0 ports are only operating at USB 2.0 speeds. The device works fine on another computer. The motherboard has both USB 3.0 and USB 2.0 headers. What is the most likely cause?
Without the correct driver, the USB 3.0 ports will default to USB 2.0 speeds.
Why this answer
USB 3.0 ports require a dedicated controller and proper driver support. If the USB 3.0 driver is missing or the controller is disabled in BIOS, the ports will fall back to USB 2.0 speeds. This is a common issue after a fresh OS install or BIOS reset.