My Sapphire Vapor-X 5770 card is making squealing noise all the time. So I contacted the Sapphire technical support. They asked me if I used a Corsair PSU, which I did. They said that:
"Thats the type of power supply that makes the squealing noise with our card. Do you have a different system you can test this card with and i am sure the noise will be gone. Our Engineers has been working with Corsair to see what is causing this so far they have not release anything yet"
Does it make sense? Is there any way to get rid of this noise?
Not really, a PSU sends power, it doesn't do much other than that, it shouldn't be doing anything unless Corsair or Sapphire screwed up on something in the powering of that card. Go ahead and follow their advice, but I suggest you don't try and use the card.
No, it does not make sense. What you are hearing originates with the coils in the power section of the GPU. You can try some of the troubleshooting tips at our forum. If they fail I'd suggest an RMA of the card. We've been down this road before with Sapphire but it's not our PSUs. If you want, we'll RMA the PSU but it's not likely to solve your issue.