XFX HD6870 upgrade from Lion to Mountain Lion

[echeclus]

Hi, I've a system with a Z68MA-D2H-B3, i7 2600k and XFX HD6870, working very well with Lion (the only problem are the USB 3.0 ports not working).
I'd like to upgrade to Mountain Lion but I know there are problems with my graphic card: is it impossible to get Mountain Lion working with my HD6870?
Are usb 3.0 ports working with 10.8.2?

 

[rodela]

At first install ML with another supported card. install mL driver 6870. then change your Graphics card and shift to 6870. may be working 100%