Here are my results, running stable for a few hours now
https://imgur.com/a/KxdIw4 x vega56 stock bios with softpowerplay mod running compute drivers
8gb of ddr3 ram
73gb Virtual memory (although 40-60 gb didn't make any difference)
Power at the wall whole system is 670w
All card are runng 900mv core except 1 that needs 910, will tinker with that one again later.
Big thanks to all the people sharing information here , it's a bit help for us newbies !