Hello everyone

My rig is 6x XFX RX 580 8gb

I mined 3 years on WIN10 with Claymore. On Claymore 14 and earliers one card in my rig always went slower - few mh/s. With Claymore 15 the problem disappeared. I mined beautiful 31,7 on every card . Now i switched to Phoenix Miner from obvious reasons. Max what i can get is 31,3 per card but again one card is slower then the rest about 6 mh/s. What can cause the problem? I switched to newest amd drivers and know when Phoenix starts i get  "UNKNOWN OpenCL Driver version". But the hashrates are as earlier - 31,3 5 cards and one around 25.

Also phoenix pauses after some time of mining - 1 hour, 2 hours up to 5h. The last command show then is PAUSE. WTF, im so new to this soft. Please mining brothers help me