Sapphire has unveiled at Cebit 2013, a Radeon HD 7950 for Mac Pro systems in order to replace the old good HD 5870 and HD 5770. The card comes with an Apple design and has the same features than the PC version:
core clock at 800MHz with 1792 stream processors, 3072MB of GDDR5 graphics memory at 5000MHz effective (or 1250MHz real speed). The PCB require two 6-pin power connectors and each power connector adapter costs $25 😀
The card is priced at around USD $450 (or $500 with power connectors adapters) and should be supported by OSX 10.8.3.
why 7950? not 7990 or 7970 ?
Good question. Maybe a problem of PSU (the HD 7970 has a 8-pin power connector that is maybe not compatible with the PSU of the Mac Pro). Actually I don’t know.
Well Apple doesn’t support Crossfire or SLI for dual die GPUs so the HD7990 wouldn’t work. I believe the Mac Pro only has 2×6-pin power connectors so the maximum power it can supply is 225W, which rules out the HD7970 (230W) and HD7970 GHz Edition (250W). The HD7950 is 180W. Sapphire could have gone with a custom overclocked HD7950 or an underclocked HD7970, but that would have required additional validation work and cost.
http://en.wikipedia.org/wiki/Radeon_HD_7000_Series
Correction, in my previous post I was quoting Wikipedia’s table which seems to be referring to typical power. The actual max power ratings are 250W for both the HD7970 and HD7970 GHz Edition and 200W for the HD7950.