You can run the Radeon RX 7900 XT with this power supply as it has four 6+2-pin PCIe connectors. The card requires three 8-pin connectors, but the 6+2-pin connectors can be used as replacements by removing the 2-pin extension. You don't need any additional accessories, but you need to make sure that the power supply delivers enough power to support the card. The Pure Power 12 M 850W provides enough power for most systems with this graphics card.