ComputerBase in Germany have spotted a Sapphire HD 7950, which is no ordinary Radeon card. This card is intended for use in Mac Pros, and while you cannot buy them anymore, it appears there is still a market for discrete graphics cards in Macs.
The Mac Edition 7950 pictured is almost identical to the Windows version, with exceptions in the cooler, clock speeds and firmware. The card is built on the older 7950 ASIC, meaning that it does not have PowerTune, and thus no Boost clocks. The clock speeds for this ASIC are 800 MHz core and 5000 MHz for the memory. It does pack 3 GB of GDDR5 over a 384-bit interface.
Beyond the clock speeds, the different cooler isn't particularly interesting. It features the same basic reference design, except that it's white instead of black and red and features the text "Radeon HD 7950 Mac® Edition".
The last difference is that the firmware is adapted so that the card will run in a Mac Pro, but the card also features a switch allowing users to switch to the Windows BIOS so that it can also be used in a PC. Undoubtedly, some users might try and place this firmware on an ordinary 7950 and see if it'll then boot in a Mac Pro.
Power is drawn from two 6-pin PCIe connectors, and display outputs include a single dual-link DVI port, HDMI and two mini-DisplayPorts.
Pricing is expected to be around €400 to €450. This is significantly more expensive than the ordinary HD 7950, which can be picked up for about €250. No word on availability.