LOUD miner works better. SRB miner not for webchain. Do not use SRB, if you want a stable hashrate.
I have 2000 h/s with my 5xRX550, but after 2 hours rig show 1600 h/s and after 5 hours rig froze.
With LOUD miner my rig works fine for weeks without hanging.
I think the algorithm doesn't work correctly with SRB miner.