ASUS B250 Mining expert problem with more than 7 cards

[Cereberus]

I have a problem at my latest build which is an ASUS B250 Mining expert with 11 GPU-s from AMD, all Sapphire Pulse Rx 570 4GB bios modded and hashing at 29.4 Mhash each. The problem is until 7 GPU-s it mines fine without problems, the moment I add the 8th-11 GPU-s it shows error, it restarts miner because of 3 GPU with errors, I switch GPU-s errors again.

Bios updated, configuration of the Bios done correctly ( I have many other rigs with Biostar Pro 250 BTC running stable from months with same cards). This is becoming frustrating so I thought to ask here in the forum.

Windows 10, with Hive OS works great with 12 cards at 350 Mhash. Still not a Hive OS fun, I want to make it to work in Windows.

Any ideas ?

[xxcsu]

The problem is until 7 GPU-s it mines fine without problems, the moment I add the 8th-11 GPU-s it shows error, it restarts miner because of 3 GPU with errors, I switch GPU-s errors again.

what gpu error you get exactly ? you got the error in windows device manager or in the miner program ?

Bios updated, configuration of the Bios done correctly

"configuration of the Bios done correctly"
what configuration are you done in the bios ? that mobo really dont need any special configuration , it should work out of the box without any problem , of course updating to the latest bios is perefered....

How is the psu set up in your sysrtem ? What psu's connected to A , B , C on the board ? what psu powering what cards , how many cards ?

[Cereberus]

Errors in the miner program, not in device manager

Bios configured
Above 4 G enabled
All slots set to Gen 1

4 PSU-s, linked in parallel, One PSU powering mobo and 3 cards, each other psu powering 3 cards. The configuration is correct as it works as a charm up to 7 cards, once I add 8-11 the Claymore miner starts to ask strange, haven't had much time to try with Nicehash maybe but I think would be the same.