to be honest i'm still working it out, my currnet settings are
--lookup-gap 2 --thread-concurrency 8191,8191,8191 -g 2 -I 13 -w 256 --auto-fan --temp-cutoff 90,90,90, --temp-overheat 85,85,85 --temp-target 68,68,68, --gpu-memclock 1500,1500,1500 gpu-engine 1065,1065,1065 --expiry 1 --scan-time 1 --queue 0
and i have undervolted my Sapphire R9 280X Dual-X OC cards to 1100/1120/1100 which seems stable right now
I haven't played with clock speeds yet
My temps come out at 67/77/67 ( the 2nd card is right next to the 3rd, but I think 77 is an OK temp now.... anyone disagree?)
Hashrates I think I'm getting 710/717/718 at max i've seen, not sure about an average yet as the numbers fluctuate pretty rapidly still rather than settling on a certain kh/s