VBoxHeadless high CPU

[cableghost2]

When my guest machine is in headless mode, VBoxHeadless consumes 7-15% host CPU constantly, when in normal mode with no applications running in the VM, there's little to no host CPU activity. Why is this?

VirtualBox: 6.0.12 r133076 (Qt5.6.2), with latest Guest Tools
Host: Windows 10 x64 Pro
Guest: Windows 10 x64 Pro

Scott

[socratis]

We need to see a complete VBox.log, from a complete VM run, where the problem occurs:

• Start the VM from cold-boot (not from a paused or saved state) / Observe or recreate the problem / Shutdown the VM (force close it if you have to).
• With the VM completely shut down (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
• Save only the first "VBox.log", ZIP it and attach it to your response. See the "Upload attachment" tab below the reply form.

Bonus if you include a similar log from when you're not running headless.

[cableghost2]

Please logs attached. Thanks for the help.

Note that in order to not interfere with the headless process, I started the VM with auto user login, if it makes a difference.

[mpack]

3D acceleration enabled doesn't seem like a good idea for a headless VM. By definition it must cause a switch to software rendering.

[cableghost2]

Not certain if this was a cause, but disabling both 3D and 2D, CPU usage down in headless mode.

[socratis]

It used to be the case up until recently, that starting a VM headless with 3D acceleration on, would crash the VM! I guess that got fixed silently but still results in high-CPU usage?

As mpack said, you don't need graphics acceleration in a headless VM, your RDP client won't use/take advantage of them.