Motherboard issue following graphics card install

[therock11]

I've been using an ASUS P8Z77-V Deluxe for years now with no issues. I recently got a new Gigabyte RX 480 video card and installed it. The first try I did it with my other RX 480 still in the system so I could use Crossfire. After I didn't receive any video with power on I unplugged the previous RX 480 and tried to boot with just the new card. I finally reinstalled all the drivers and went to a previous version of the AMD drivers and it was booted and running. I then tried it with the second card again and it booted. Now I have a high pitch whine from my speakers after windows begins to boot and it doesn't go away. It actually gets louder depending on what is displayed on the screen. I tried with just my old card and the sound is still there. Here is where it gets odd. My motherboard AI Suite is now giving me readings that the CPU fan is at 0 RPMs even though my PSU CorsairLink software says everything is fine. Then just now my motherboard temp changed to -61.0 celcius. Do I have a failing motherboard or could this be power supply related. I have a Corsair HX750i that was just installed early 2016.

 

[mdd1963]

Does the MB's BIOS have options for configuring PCI-e lane config (8x + 8x?) for the pair of GPU-length slots for SLI/CF?

(Confirm CF is supported on this board?)

 

[therock11]

Does the MB's BIOS have options for configuring PCI-e lane config (8x + 8x?) for the pair of GPU-length slots for SLI/CF?

(Confirm CF is supported on this board?)

This is from the specs page on ASUS.com

Multi-GPU Support
Supports NVIDIA® Quad-GPU SLI™ Technology
Supports AMD Quad-GPU CrossFireX™ Technology
Supports AMD 3-Way CrossFireX™ Technology
Supports LucidLogix® Virtu™ MVP Technology

I've run with a dual GPU setup for months now with my Sapphire RX480 Nitro and a Sapphire HD 7850 and had no issues.