OCC has published a new review on the Sapphire HD 4770

The cooling solution is far from what you normally see with a reference card; the use of a dual-slot solution instead of the single slot used in the HD 4850, HD 4830 and HD 4670. This is a welcome sight since subpar cooling and excruciating noise were a fact of life when and if you could adjust the fan speed. The cooling solution on the HD 4770 looks much like an Intel CPU heatsink and does an admirable job in dissipating the heat generated by the 40nm core. When overclocked, I measured load temperatures of 50 degrees Celsius when the fan was run at 100% and 60 degrees when the drivers were in charge of the show. Even at 60C I did not see any performance issues due to heat. With an open design like this though, there is one drawback when used in a less than optimally vented case; most of the heat generated will be discharged into the case, driving up component temperatures. The upside here is that the fan noise, while audible, is not what I would call incredibly loud. It was audible over my Scythe Kaze fans, but the pitch was not such that it was out of the norm driving me nuts.

Sapphire HD 4770 Review