I was on 12.2 yesterday but I did update this morning to 12.3I've used my method before to diagnose a noisy cheap TV so it does work it might not be as practical but it works.
As for the motherboard not supplying enough power the vid card should pull the extra power it needs from the 6/8 pin PCI-E power connections. What driver version do you have? Have you updated them recently?
BTW: first post is updated with more info, my second card isn't being used properly (at least not the way I expected it to be)