Btc-t37 only able to use onboard graphics, wont detect gpu

Bought one of the 8 gpu riserless mobos to play around with and when i install hiveos it only detects the onboard graphics.

When I try to install windows and using newest drivers the card does not get detected either. Tried 3 slots. plugged in power to riser and then power to graphics card. Graphics card pulled from working miner. Am i missing a setting or something on these?