R720: GPU IS DISABLING LSI 9200-8E HBA (IT) CONTROLLER

Hi,

I am having an issue with my 9200-8e SAS HBA Controller that is flashed to IT mode (v20.). It works perfectly when no GPUs are installed but as soon as I install one GPU, the HBA controller stops working.

My Setup:

Dell R720 with the following specs:

 

• UNRAID 6.10.3 Pro edition license
• Xeon E5-2670 115W CPUs
• 384GB RAM
• Onboard H710P HBA controller flashed to IT mode - Runs the 8 drives int he R720
• Dual 1100W PSU
• iDRAC
• Broadcom integrated 4 port 2x 1GB + 2x 10GB NIC
• Riser 1: (3x X8 CPU2)
• Riser 2: (1x X16 CPU2 & 1x X8 CPU1)
• Riser 3: (2x X8 CPU2) - Note it is not the GPU Kit version

 

I have the following cards in the server:

Riser 1: LSI 9200-8e plugged into slot 1 (X8 CPU2)

Riser 2: empty

Riser 3: empty

 

I have an MD1200 plugged into the LSI 9200-8e card above.

This is working as expected. The LSI card and the drives in the MD1200 can be seen by UNRAID under Unassigned Devices.

 

The Problem:

When I plug a GTX 1080 Founders Edition GPU into Riser 2 - Slot 4 (X16 CPU2), using the Dell GPU power cable plugged into the riser and the card, the LSI 9200-8e is not seen by the server.

Everything else continues to work as expected, including UNRAID and the 1080 GPU.

I can even see the 1080 GPU under UNRAID and am able to pass it through to a VM and it works.

I tried moving the LSI card into slots 2 & 3 to see if it made any difference but I still get the same outcome.

Any ideas? Do I have a conflict with the PCIe slots? How would I resolve this?

Thanks,

Brenton