[SOLVED] 2 Mobo + 3 graphic cards = no luck

jpt7505

Honorable
Mar 25, 2015
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10,510
I've been attempting to run the following system with no success and wanted to get some advice from the community.

MB: Asus Tuf x299 MK2 latest bios
Cpu: i7 7820x

1500w Power supply

Graphic cards:
Quadro M6000 (12Gb)
Titan X
Titan V
-All non-sli-

This is a Post Production Machine and I use the GPUs for rendering. Due to my case I must use an extension cable (riser) for the third slot however the cable has been confirmed to be working.

Whatever GPU gets plugged into the third slot does not register in device manager or my applications. I've gone through two motherboards (both the same model number and series) with no success.

The Mobo had 44 lanes while the CPU has 28

I have also attempted to use an older GPU as a variable (GTX680) and still no success.

My conclusion is this will not work and I have no idea why or I've gotten two bad motherboards.