First, here is my setup, running Unraid 6.9.1:

• AMD Ryzen 3950x, 16 cores 32 threads
• Gigabyte AORUS Master 570x with F33a BIOS
• 64GB of RAM, (4x 16GB DDR4 3200MHz CL16) 
• EVGA RTX3070 XC3 (first PCIe slot)
• MSI Radeon RX580 GPU (second PCIe slot)
• 2TB m.2 NVMe SSD
• 500GB m.2 NVMe SSD (used as cache)
• 3x 10tb HDD

I recently added the RTX3070 GPU to my setup, which forced me to slide the RX580 to the second PCIe slot on my mobo. I'm using the RTX GPU for my windows VM, and my RX580 for my macOs VM. Since I did the installation, as soon as the system is running, the RX580 fans are spinning until the gpu is passthrough to a VM. That had me questioning on the power usage. If the fans are spinning, the GPU is clearly not in sleep or low power usage state. 

So, I though it would be a good idea to enable the AMD gpu driver on Unraid, so that Unraid would take care of the GPU and put it in sleep state until it is passthrough. It does work. I have no problem starting the macOS VM with the RX580. However, every time I shutdown the VM, the whole system crash (the system reboots). It seems like Unraid fail to take back the GPU from the VM. 

To sumerize the whole thing, I'm looking for a way to keep my GPU quiet and low power usage mode until it is passthrough to a VM, without crashing the whole system. 

 

When available, I'll share with you the Unraid logs, as it may be a bug that is worth to fix.

Edited March 18, 20215 yr by Satris

 

Thank you @trurl for your reply. However, the problem doesn't seem to be related to the CPU and the c-state issue. First, my DDR4 memory is not overclocked and is compatible (if we refer to the chart from the web page you shared). Moreover, the system crash only happens when the Unraid AMD GPU driver is active, the device is not bound to the VFIO and the VM release the graphic card.