Higher power consumption when running headless

[donoewan]

Hi all,

It seems my power consumption is higher (when idle) after booting the PVE in headless mode (no monitor connected). After connecting and disconnecting a monitor, the power consumption drops with 3 to 5 watts.

My guess that it has to do with initializing the frame buffer which seems not present after booting headless.

After booting headless:

root@pve:~# lshw -C display
  *-display                
       description: VGA compatible controller
       product: Phoenix1
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:6c:00.0
       version: 05
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi msix vga_controller bus_master cap_list
       configuration: driver=amdgpu latency=0
       resources: iomemory:fc0-fbf irq:39 memory:fce0000000-fcefffffff memory:dc400000-dc5fffff ioport:e000(size=256) memory:dc900000-dc97ffff

After monitor connect&disconnect:

root@pve:~# lshw -C display
  *-display                
       description: VGA compatible controller
       product: Phoenix1
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:6c:00.0
       logical name: /dev/fb0
       version: 05
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi msix vga_controller bus_master cap_list fb
       configuration: depth=32 driver=amdgpu latency=0 mode=1920x1080 resolution=1920,1080 visual=truecolor xres=1920 yres=1080
       resources: iomemory:fc0-fbf irq:39 memory:fce0000000-fcefffffff memory:dc400000-dc5fffff ioport:e000(size=256) memory:dc900000-dc97ffff

I can try ordering a virtual display port dongle but I rather prefer to solve this by configuration.


Can anyone help me resolving this issue?

Thanks in advance!

HW Setup:
AMD Ryzen 5 8600G w/ Radeon 760M Graphics (iGPU)
Asrock Deskmini X600

 

[dakralex]

Welcome to the Proxmox forum, donoewan!

It might be worth a try to use amdgpu's virtual_display kernel parameter to setup a virtual display device [0]. You can pass it to the kernel parameters in the same way as you would do for others in the /etc/default/grub file, e.g. amdgpu.virtual_display=xxxx:xx:xx.x,y.

[0] https://docs.kernel.org/gpu/amdgpu/module-parameters.html#virtual-display-charp

 

[donoewan]

Thanks Daniel,

The change you proposed does indeed add the virtual display and lshw does indeed show up with the same info as when I connect a real monitor.

It didn't however reduce the power consumption as with a real monitor connected.
Another downside is that when using a virtual display, phisical output is disabled: https://bugzilla.kernel.org/show_bug.cgi?id=203339. This can be painfull / cumbersome when there are issues with the PVE.

I will order a virtual display dongle and let you know if it resolves the problem.

Best regards,

Paul