I just upgraded from a Amd 7770HD to a R9 280. I have an Antec earthwatts 650. problem is, it only has one 6+2 pcie connector. I thought it had two but I realized that the 6-pin P4 connector is not for pcie. so question is, would it be safe to use a 4pin molex to pcie adapter or should I just upgrade my psu?