I have a r9 290x and I'm thinking in buy a r9 390x, the crossfire will work ? or should i buy another r9 290x ?
I pretty sure you can. You could with the 7970 and 280x it's the same thing but it might only be 4GB.
Just a few posts beneath yours > Crossfire with r9 290 and r9 390?
Retrieving data ...