Chipset USB wiring was physically connected as per the board layout.
Chipset USB wiring was physically connected as per the board layout.
I discovered yesterday that USB connections for various chipsets and PCHs are arranged in unusual ways. Typically, these components only support USB 2.0, but manufacturers sometimes mix in USB 3.0 capabilities. They connect the USB 2.0 link with SS pins and sometimes use PCIe connections for those pins. After wiring, they program the chipset to recognize USB 3.0 as the active interface. For the X570, there are two USB controllers, each with six USB 2.0 ports, and four of those can be linked to SS pins for USB 3.0 functionality. Regarding the Intel PCH Z490, it has 14 USB 2.0 ports and can connect to six HSIO ports for USB 3.2 Gen 2 or Gen 1, plus four more HSIO ports shared with PCIe lanes. Unlike AMD AM4 CPUs or APUs, the Intel CPU lacks USB ports, which raises questions about why they had to combine signals from different buses.
To ensure continued support, many devices require no more than the bandwidth of USB 3.0, let alone 3.1 or 3.2. For assistance, enabling legacy compatibility mode in the BIOS can help when USB drivers aren't available and performance is poor. This approach works for running Windows 7 on Z390, and since the USB driver for Z170 is comparable, it's possible to install a 3.0 driver on Windows 7—though it may be challenging.