According to a forum post on tonymacx86, Apple’s latest release of Mountain Lion, the 10.8 developer preview, is able to natively support AMD Radeon HD 6950 and 6970 without the need for any tweaks or hacks. As for the 6950 and 6970 specifically, the reports originate from the netkas.org forums where several posters report a 6950 running Netkas EFI working natively in 10.8. One poster even reported the 6950 continues to be recognized in Lion with unmodified drivers after “warm booting back to Lion from Mountain Lion.”
There are still issues, as tonymacx86 posters pointed out: “It looks like the 69xx situation seems a bit immature and experimental at this point. Even in the new OS.” Another forum poster claimed NVIDIA 5xx cards also seem to run natively with mkchis claiming full support for the GTX 570 graphics card with no hacks or mods. He said it is “running at full res even smoother than a patched Lion. It’s like native.”
When it comes to booting from Mountain Lion to Lion with unmodified drivers, one poster warned it does not seem to work if you are connecting a display to the 6950. The good news is a prominent hackintosher informed us that Chimera was updated to run on both Lion and Mountain Lion with a dev release coming within days:
We’ve fixed Chimera to work with both LIon and Mtn. Lion- there was a small change necessary to boot 10.8. We’ll be releasing that in a day or 2 for devs.
As a side note for Mountain Lion support, Robservatory shared its method of getting VMware Tools to work when running Mountain Lion in VMware Fusion. According to the post, Mountain Lion “will kernel panic” when trying to install VMware Tools. Here is the fix: