As long as I had my XFX 6800xt, I had some temperature problems. The GPU temperature went up to 80°C and the hot spot temperature usually stood at 105°C, but occasionally went up to 110°C. So the fans were screaming as if they were being slaughtered.
So I removed the shroud, replaced the 90mm fans with 120mm fans, which I had lying around in my “tech box” and which are now hanging on the heatsink through zip-ties. And a 100x100 3mm thick thermal pad between the backplate and the back of the board.
Result: Furmark (as an extreme example) just manages to bring the respective temperatures to 57°C GPU temperature or 75°C hot spot temperature.
I would never have thought that an investment of €8 could make such a difference
Fans did the thing.
Thermal pads on the backplate affect temperatures, but only to a degree. They certainly can´t affect core temperatures.