Thank you for the additional information,
Since I am not an HP employee I can't answer your questions about why there aren't certain components. Here is the information for the video cards:
Graphics cards
● PCIe Gen3 (PCIe3) bus speeds; can support three PCIe Gen3 graphics cards in PCIe3 x16 slots
● Up to one 150 W or two 75 W graphics cards with 850 W power supply
● Up to two 300 W or three 225 W graphics cards with optional 1125 W power supply (other configuration restrictions may be required)
It appears, however, that the two 300W video cards are with the optional 1125W power supply unit (PSU).
With the standard 850W PSU, only one 150W video card can be used. The PCIe slots provide 75W of power each without an additional power dongle.
