Asus Z10PE-D8 WS Multiple GPU Bios Settings

Can anyone point me in the right direction for setting up the bios for installing 3 XFX AMD Radeon Vii GPUs on the Asus Z10PE-D8 WS.

I am trying to install three graphics cards on this board but so far I can only get one of the XFX AMD Radeon Vii GPUs to install in a windows 10 64bit environment.


My computer specs are as follows:

I have a Corsair ax1500i power supply with 1500 watts of power.
Motherboard: Asus Z10PE-D8 WS
Processors: 2 x Intel Xeon E5-2670 v3 @2.30 GHz (12 Cores each)
RAM: Crucial DDR4-2133 ECC 128GB
GPU 3x XFX AMD Radeon Vii Graphics Cards with 16GB HBM2 Ram Each (48 GB total)
OS Drive: 500 GB Samsung 850 EVO
Optical Drive: 24x DVD-RW DL
OS: Windows 10 Professional

I have the latest bios flashed (4101) on the Asus Z10PE-D8 WS motherboard.
I don’t think that I need to enable the PCI-e slots since one of the three Radeon Vii cards works in any of the slots but the other two Radeon Vii Cards i cant get to show up or be recognized in the windows device manager or in any of the slots.

If you can help out with some bios pointers I would be very thankful.