@Claymore,
Could you please check memory controller load? As others stated some cards randomly gets lower load on memory controller and this causes decreased hashrate.
For instance, my average hash rate should be around 264,5 MH/s for my 9 gpu rig. But it displays effective hourly rate around 205.0 MH/s.
I have tested this for more than 7 hours and this is the case for me. Even on ETH only mining using fine tuning and low power bios.
If you see low values on pool, miner must show low speed too. If you see that speed is not constant in the miner, change -dcri value, there are some border -dcri values where it can have unstable speed.
Thanks for the reply.
I have already specified -dcri value and found the best setting with -7 for ETH only and -25 for dual mining. However, even using these settings speed on miner drops and goes back to actual rate from time to time. So to confirm you, speed on miner drops and pool is affected from this as a result.
I'd think my gpus are bad but as soon as i switch to an older release (8.1 or 7.3) ETH only mining is stable. Dual mining is also stable but I'll lose the speed boost you provide with 9.
Also it can be bios or throttling. If you are sure that it's not the case, use "-asm 0", I don't see this behaviour on my GPUs and don't have other ideas how to fix it, sorry.