NOTE: This solution is for DSS V7 system
This issue was observed on some Supermicro motherboards: NIC is not visible in DSS for configuration, but the driver is loaded and card information can be seen.
To fix it, enter BIOS > "Advanced Chipset Configuration" > "Enable VT-d" and change its state to "disabled", then boot into DSS.
Card should now be properly recognized and ready to configure.