Low hash rate on 2nd and 3rd GPU


I’m running ethos distro with the Claymore miner on a Asus “P8H61-M Evo” board with three RX480 GPUs. All GPUs are connected with riser boards.

While I’m getting hash rate of 275 H/s on the first GPU, the other two GPUs are on 63 H/s. I’ve upgraded BIOS of the motherboard to the latest version, but I’m kinda stuck now. What could be the reason for the low hash rate?

Try rotate the GPU. If 1st perform bad in 2nd slot, maybe the riser or the sysboard has a fault.

My gpu 1 needs sometime a bit to get the full sol rate, sometimes up to 2 hours.

You could try a benchmark or a other pool to verify the sol problem.
Maybe a other mining software? Newer/older/different one

I would suspect the MB itself. but as zPools suggested, rotate GPUs. If first slot always gets higher rate than slots 2 and 3, (and raisers are good) , then its the MOBO.

Thanks a lot for the help. I’ve replaced the board and now I have the same hash rate on all GPUs.