TechPowerUp posted a review on the Sapphire R9 285 Dual-X OC 2 GB
A quote from the article:
Today AMD launches the Radeon R9 285, based on their brand-new Tonga GPU, which replaces Tahiti, promising to be faster and more power efficient. Sapphire's board comes with a custom cooler and is overclocked out of the box for some extra performance.Sapphire R9 285 Dual-X OC 2 GB @ techPowerUp