I have a mainboard with 2 HD 6990's attached already and wanna upgrade with one more card - a 7990.
The problem is that the 6990 drivers do not support the 7990 officially and the other way around.
I do cryptomining - so I don't need game support or something like this.
Does anyone know if it possible to run those cards together on one board?
I know that it's not tested... but if AMD themselves doesn't know if it would work - who then?
I won't buy a 450€ card if I don't know if it would run.
This is not a combination that we are required to test.
However. as the previous suggestion said, go back to the last common driver for both the products.
We've already answered, this configuration is not recommended, supported or tested by AMD so we cannot promise you it will work.