@leonix007 The latest 18.2.1 drivers claim to support both as well. Ive tried them all after first uninstalling any trace of the cards from the computer and The RX470 is only recognized for what it is by its own ASUS drivers and performs by far the best with them. Crimson, adrenaline or any other amd driver all drop the 470s hashrate by 10%-20%. probably due to the mis identification as a 570 and the Asus drivers are even worse for the sapphire 580. I have already flashed modified bios onto both cards, which made some improvements but If I want max performance, which, who doesnt? Im going to need to use both drivers... there has got to be a way. My Intel IGD drivers run flawlessly alongside either the Asus or AMD drivers, doesnt effect either card in any way. So it is definitely possible...just gotta figure out how....come on bitcointalk.org community....I will for sure hook somebody up with a minimum of .0001 btC for a solution.
I feel you bro, I have one rig with mixed AMD and Nividia and doing headache, anyways, looking at your prob I have a feeling it might be the clock issue, did you use MSI afterburner to do clocks? since this is a different cards it should be configured on each card.
just ensure that amd drivers is in Compute mode.