I believe the some of the cables are keyed differently at the PDU end vs the peripheral end. If you look at this picture --
https://www.evga.com/articles/00844/images/hero/1200P2_Mod_Face.png Notice the VGA ports have square top and round top pins. They are in a different configuration on the PDU than the graphics card requires -- See this graphic -- https://www.techpowerup.com/forums/attachments/1000x2000px-ll-ac82eb1d_pinout-png.94991/
The CPU plugs may be the same on both ends. The motherboard end is traditionally the split 4+4 end incase the motherboard only requires 4 pins.