RX 470 and PSU issues

[Luke62]

I recently purchased an RX 470 and was trying to install it today. It has an 8pin power input and my PSU has 2 6 pins. When only 1 6 pin is plugged into the GPU, the PC will start and the GPU's fans will run but the monitor receives no signal. When I use my 2x6pin to 8 pin adapter, the PC won't even boot up. I am not sure what model my PSU is, but it says 100-240V input at 50-60 Hz and 460W DC output, which I assumed would be enough. Any suggestions?

 

[DSzymborski]

Post an image of the label and any other identifying marks. I've seen "450W" and "500W" PSUs that only had 200W available on the +12V rail. This is important information that you need to know before making *any* GPU purchase and that we need to know to give any competent advice.