Never use psu (adapter) from China .. blown a few already.. use PC's psu.
Not sure what's the startup amp .. but your psu is 12v 10a? it can only support max 2 GS in dual mine mode.
Anyone know of a source for the ATX PCIe (and molex) to barrel plug adapters?
Seems CabelZ is no longer making them...
Or just buy some 18-gauge wire, cannibalize a PCI-e or Molex extension cable and use these: