Working just tried -mt 1 but not very good results 480 makin 29mhs and 570 making 25mhs. my total rig with claymore was 217mhs now with phoenix 199mhs.
Why don't you mod your bios?
I know its not bad option but i liked the way keeping stock bios. AMD mem tweaks allows to do it but i couldnt find yet for RX cards.