Is this okay result?
OS: Windows 7
Miner version: 12.4
GPU: Club 3D R9 280x RoyalQueen
Clocks: 1000/1500
Voltage: 1.05V
Hashrate: 290H/s
Modded memory straps, bios found on internet.
Yes. But you may try to OC memory. Try memory clock 1501+MHz - will be next stripe. I'm use Asus 280X 1.1V 1100/1600 with modded bios, 17.4.1 driver Windows 10. 330 H/s on miner 12.2. 12.4 is unstable and each 1-1,5 hour hangs.
Default is 1.2V 1070/1600 without bios mod - 300 H/s.
P.S. In driver version 17.4.1 AMD adds wattman compatibility for 200-series cards. It's very useful, much better than Overdrive. But in 17.4.2. they disabled wattman and enabled overdrive again... It's strange... If wattman can work with 200-series cards as in 17.4.1., why disable him in 17.4.2...