Tried the config you sent, one GPU is fine but about the same hashrate (215KHs), the other GPU doesn't like it for some reason. Both are the same brand.
http://i.imgur.com/pLIFsqy.jpg
Please disable in AMD-CCC grafic-overdrive.http://i.imgur.com/pLIFsqy.jpg
The GPU-core depends on the vendor of your hardware: i'm using a r9 280x from powercolor(a cheap vendor) and have a GPU-core of 970 with 330kh/s.
On Sapphire cards i'm using a gpu-core of 1050 with 350kh/s.
diff of 20kh/s => at atm price ~ 22$ per yeah diff
but costs me 50 bucks less when buying new => 2 years ROI 