I am trying to replace my existing graphics card with a RX5700 Sapphire. The PSU supplies only a single 6-pin PCIe, but the impression I get is that this is sufficient to power up the card even if not to get the highest level of performance. But when I install it I get a Hardware Not Detected error. I know it's powered since its on-board fan runs and the card is well seated in the slot. I've updated the graphics drivers to the latest available, but it's not installing the correct one because it's not detecting the new card.