I have searched high and low, but i have yet to find the answer.
Back in 2005 When Crossfire was new, it was said that running 2 GPU's at different clocks would improve performance, or at least see no loss.
E.g Running one card with 800mhz and the other with 900mhz.
These days, things are different.
When running e.g one 7970Ghz and one 7950 in crossfire, the 7970Ghz will downclock to match speed of the 7950.
This is covered in the AMD FAQ on Crossfire.
What I would like to know is, when was this feature first added to the AMD systems?
I would like to have a full date, link to arctical or information about this change. Maybe which driver version this change was added into.