If you have an Intel server board that requires a 24-pin ATX power supply, you can don't have to run out to purchase an expensive power supply with 24-pin power connector. You can just use this adapter cable to make your existing standard 20-pin ATX power supply work as a 24-pin ATX power supply. Cable length is about 6 inches

Connect to 20-pin Standard ATX Connector
Connect to Intel Server Board 24-pin Power Connector