GPU mining rig problem

[marcelll]

Hi guys
I have mining rig with this assembly:
13 x AMD Rx 560
Asrock H110 probtc
4 Gb ram DDR4
Intel 1151 3900
SSD 128-256gb
13 x Riser
evga 1600 w
and I have problem with mining if I mining any crypto currency a long time. I can mining 1 or 2 days with stable hashrate 180mhs but if this miner mining more than 1 or 2 days miner mining on 60-70% performance and I don't understand why?? At room is normal temperature.


Photo: https://ctrlv.cz/wUw5
Photo statistic: https://ctrlv.cz/dsTl
Photo configuration: https://ctrlv.cz/wDgN


Thank you for any answer