Hello,

I start by detailing my configuration:

 

unRAID 6.3.5 Pro with :

 

                           MB : ASRock X99M Extreme4
                          CPU : i7-5820K CPU @ 3.30GHz (6 cores / 12Threads)
                         RAM : 64 GB DDR4
                        GPUs : 1 x NVidia GTX 970 & 1 x ATI Radeon RX 480

 

I wish I could use the 2 video cards in my VMs simultaneously.

 

I tried several tutorials dedicated to that but if one works normally (normal is the second card), the primary display goes black and nothing happens.

 

I tried the card Radeon RX 480 in primary then the GTX 970 (and even a 750 Ti), nothing to do.

 

Is it possible to boot aRAID without any video output so that it does not interfere in the primary display?

 

My motherboard has 3 PCI-E ports but the last one is used by an 8 ports SATAIII controller so I can not release it.

 

Is it my graphics cards that are not fully compatible? If not, what are the most appropriate graphics cards? (GeForce of preference)

 

Thanks in advance

Quote

 the primary display goes black and nothing happens.

 

That sounds like you need to dump your GTX970 video bios to a file and then added it to your VM's config file. Check out: this thread on, "How to pass through an NVIDIA GPU as primary or only gpu..."   I recommend trying to dump your own video bios, rather then using provided links in the thread (for best functionality/compatibility). 

already tried ... Black screen