Okay, to start, I had do dig for a bit to find the specs for this PSU. Apparently the 12 volt rail only provides 14 amps. The GPU you bought requires 22 amps at the 12 volt rail. So, to start, you need to buy a new PSU. It is off brand, not well made, and well, that's all I'm going to say. Before you do any more searching about problems, this problem(the PSU) needs to be addressed.