Do any of you have the following problem:

I have a multi Vega rig, and followed the following steps:

Fresh Ubuntu 16.04 install.
Installed ROCM  1.8.1 (honestly I dunno where you guys find 1.7.1).
Reboot
run the export HSA_ENABLE_SDMA=0 command
Set fans to 70%
Run the miner

Then what happens is I can mine with one Vega, but as soon as I add an additional one, and then try to run the miner, my PC either freezes or the red lights on Vega no2 goes off

Note: I do not have a PCIE Gen3 mobo. Its an MSI G890-GD65 with an Fx8370 CPU.

Any help will be appreciated, I have 7 Rx570 / Vega rigs I need to get on the network I can offer 0.05 ETH to someone who can help me fix this problem.