My graphics card was overheating, but overall system temperatures are fine. The card obviously needed new thermal compound. On every video walkthrough of this process, you will see that the first step is removing the backplate. But not on the Gigabyte R9 390 GV-R939G1 GAMING-8GD G1.
When you try to remove the backplate, you will find screw mounts like this instead of normal screw holes.
As I found out, you don’t need to remove the backplate with this card! Just remove the three screws on the far side of the card, then remove the 4 GPU heatsink screws, and gently peel the heatsink off of the card. Be careful not to break any of the power cables for the fans, and try not to damage the little glue pads that help the card avoid causing reverberation and noise.
Here’s what the stock thermal paste looked like:
Not the worst I’ve ever seen, but it’s obviously not doing the trick. I wiped it off with rubbing alcohol, put some Arctic Silver 5 in its place, put the card back together, and I’m averaging about 15 degrees cooler than before. Perfect!