You need to buy an adapter that can convert your power cable to a 6pin so as to be able to connect it to the gpu.
I found one that can work on your gpu considering you have two molex cables available on your psu: http://www.lunashops.co.uk/images/upload/Image/2-4-to-6-cable-1.jpg
You need to buy an adapter that can convert your power cable to a 6pin so as to be able to connect it to the gpu.
I found one that can work on your gpu considering you have two molex cables available on your psu: http://www.lunashops.co.uk/images/upload/Image/2-4-to-6-cable-1.jpg