Yulsiera :
clutchc :
If the PSU is the MC or the HC, it will be fine. If it is one of the low end 600W models, it will work, but don't know for how long. Does it have 2 x 6/8 pin connectors?
it does have the 2x6 pin connectors
Most R9-280X require a 6 pin and 8 pin for power. That doesn't sound like a very substantial "600W" PSU. Most 600W PSUs have 1 x 6 pin and 1 x 6+2 pin connector.
PCIe X16 slot: 75W capacity
6 pin connector: additional 75W capacity
8 pin connector: additional 150W capacity
That's a total of 300W capacity. The extra wattage is needed for OC'ing. If the card doesn't start, you may need something like this to fool the card into thinking all pins are populated: http://www.newegg.com/Product/Product.aspx?Item=N82E16812200420