Are any of these heatbag gpus made by Sapphire ??
I've been noticing that they have been skimping out on the 7xxx gpu and vrm heatsinks... :/
I bought a Sapphire HD 7870 Dualx then returned it 9-10 days later after noticing there was nothing cooling the vrms. The revised and very weak Dualx hsf also played a part with that decision.
Those are sapphire I had issues with a single MSI a month or so ago as well although it ended up being a bad card.
Replacing the stock thermal paste should bring the temps down 1-5c and give you an idea on how flat the gpu/hsf contact surfaces are. I have also made gains by reseating the vrm heatsink and/or modding the thermal pads by realigning them or by removing the excess.
Doing this will void the warranty with Sapphire but shouldn't be an issue because the gpu will pay for itself well before it breaks down.
I gave up with trusting any company's factory cooling setup years ago. eg. the mobo's vrms an nb used to get a bit warm..