Dell 12th/13th gen Intel cpu motherboard socket vs PSU plug compatibility

There are three versions of Dell proprietary ATX12V socket on motherboard: 8 pin (Optiplex 7000, Inspiron 3910), 10 pin (XPS 8950, Aurora R13), 12 pin (Aurora R15, XPS 8960).

460w/500w PSU 8 pin connector can plug in 10 pin socket 

750w/1000w PSU 10 pin connector can plug in 8 pin socket

1350w PSU 12 pin connector can plug in 10 pin socket (and probably 8 pin socket too)