I have an add-on card on the RSC-R2UW-3E8 riser card in slot 2, but it cannot be detected in your X8STI main board. How can I get this combination to work?
In the BIOS (Advance >> PCI/PnP Configuration), change the option for PCI-e Width from [X16X8] (default) to [X8X8X8]. Then, change the option Rom for PCI-e Slot 2 from [Disable] (default) to [Enable]. Now the device on riser card will be detected.