On its Facebook page, PowerColor has teased its passively-cooled Radeon HD 7850 SCS3 graphics card with the slogan that "silence is golden" and "no fan means no noise." Though the company has yet to provide any specific information, it appears to use a reference PCB and will presumably have the reference clock speeds of 860 MHz for the GPU and 4.6 GHz for the 1 / 2 GB of memory.
Though we don't doubt that the efficient HD 7850 could function in this form, it is imperative that if there is any attempt to passively cool a graphics card, use a case with excellent airflow to prevent overheating.
The PowerColor HD 7850 SCS3 will be "released soon on the market" with a still undetermined price. It is the only retail, passively cooled version of the Radeon HD 7850 of which we are aware.