Well, it was kind of expected, but it was worth a try.
If you read the manual of any recent motherboard, you see that installing a M.2 SSD disables two SATA ports.
The Q1900DC manual states that the minipcie connector only can be used for a wifi module, but it seems it can be used for anything.
I am currently copying files back to redundant storage (new xpenology install and I see that the CPU maxes out at 25%. Neat.
Is that because I have an Intel nic installed ???
If I replace that with a pcie SATA card and using the Realtec motherboard nic, are there some performance penalties for that stunt ???