Sorry if this is in the wrong thread, but I believed this was more power supply dependent. I built a computer about 4 years ago, but recently I realized I should probably upgrade some stuff. The first thing I was looking at was the graphics card. I decided on either the Radeon r9 380 or GTX 960. I realized though that I wasn't sure if my power supply could handle it. I'm not sure if it has the 6 pin power connector or not. This is the power supply I have.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182075
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182075