Summary: AMD's Radeon HD 5670 can successfully improve over the aging HD 4670. It offers 20% more performance without any power increase or extra heat. This allows AIBs to build cards that are extremely quiet, in our case the HIS HD 5670 IceQ is the quietest actively cooled card that I ever tested.
Pros: Solid performance upgrade over HD 4670, Extremely quiet, Custom design, 40 nm GPU, Support for DirectX 11, Support for AMD EyeFinity Technology, Native HDMI, Low temperatures
Cons: Fairly high price, Higher idle power draw than other HD 5000 cards, No support for CUDA/PhysX