The MSI R9 270x G2 is listed here http://www.verters.com/vertcoin-hardware-list to get 400 KH/s
They are using this config:
--gpu-engine 1050 --gpu-memclock 1210 --auto-fan --temp-target 80,75 --temp-overheat 90 --temp-cutoff 95 --gpu-powertune -20 --worksize 256 -I 16 --lookup-gap 0

Can anyone confirm this? Anyone got this card to try it?
Thanks