Ty Clay for your job. Tahiti is a best choice for rest again. Your miner its all that needs.
7*Tahiti Islands (6*R9 280x + HD 7970) + Hawaii Island (R9 290) + 2*Tonga (R9 380x and R9 380 4 Gb) increase summary hashrate from 220 H/s(genoil-miner v0.5 and v.0.6) to 450 H/s(Claymore ZCash AMD GPU Miner v. 1.0) ,all cards working on default settings,AMD Radeon-Software-Crimson-v.16.10.3-27Oct.
Claymore ZCash AMD GPU Miner v.1.0 turn hashrate of Tahiti GPUs up to 43-45 H/s ,Hawaii GPU show same 44 H/s, Tonga GPUs shown 33 H/s ( R9 380x) and 31.5 H/s (R9 380 4 Gb) ,all cards working without any issues and show max temperature 63 degrees Celcius in mining mode. Fan load max on 54%.
BRAVO CLAY!!!!! R9 280x again show its real power.
Hope Linux version would be ready soon and getting us same or may be a better results