Gpu mining problem rx470 / rx480 / rx570 / rx580

Hello, miners,

I am struggling for days to configure my rvncoin miner. I was mining for a month ERG and now i decided to switch to rvn. The problem is that all of my gpus (listed in the title) are getting around 7.5 to 10 mh/s each and I’ve read that they should make around 12-13 mh/s each. I’ve played for days with the mhz and mV. I am using simplemining.net and yes all of the cards are with moded bios. So do you have any clue what might be the case?

Thanks in advance! 🙂