virtualbox.org

My VirtualBox has been working properly for nearly one a half years running an Ubuntu guest on top of a Windows 11 host.

Suddenly it stopped working after an automatic Windows update last Monday. I couldn't event start the machine. I upgraded to the latest version (6.1.36) and the I could manage to boot, but the performance was really degraded with constant "hangs". I tried with "not so recent" versions to see if there was some time of recent "regression", but switching back to 6.1.30, the problem persisted.

After doing (lot of) tests I found that the problem was due to my Energy Plan Settings. In "Windows Start" -> "Edit power plan" -> "Change advanced power settings" -> "Processor Power Management" -> "Maximum processor state" -> "Plugged in" the value 90% was set. (I changed it a few weeks ago since I notice much lower CPU usage than using just 100%). When I restore it to 100% and then on my VM setup I limit CPU usage to 90% (with KVM ) everything looks to be working properly again and also the CPU thermal behavior becomes "normal".

Not sure whether this is a Windows, Intel CPU or Virtual Box problem. I'm tuning an Intel i7-10850H CPU with 16.0GB of RAM and Windows 11 Enterprise (Version 21H2, OS build 22000.856).

I guess this problem can affect many people not using the default Windows Power Plan setting.

Thanks for your information! Here are a couple thoughts:

earizon wrote:automatic Windows update last Monday. I couldn't event start the machine. I upgraded to the latest version (6.1.36) and the I could manage to boot, but the performance was really degraded with constant "hangs".

Check the VM's Status Bar for the green turtle: If you see the little dear, it means Windows has enabled Hyper-V, which could cause degraded VM operation. See HMR3Init: Attempting fall back to NEM (Hyper-V is active)

earizon wrote:"Maximum processor state" -> "Plugged in" the value 90% was set. (I changed it a few weeks ago since I notice much lower CPU usage than using just 100%). When I restore it to 100% and then on my VM setup I limit CPU usage to 90% (with KVM ) everything looks to be working properly again and also the CPU thermal behavior becomes "normal".

It is not necessary to adjust processor caps in either host OS or Virtualbox settings. If not doing so on your PC makes the CPU thermal behavior not be "normal", as in it overheats, then your PC's cooling system is inadequate. Install better heatsinks, increase airflow, get the PC box out of the cabinet it's in, etc. 100% on all processors should be possible with adequate non-budget-breaking cooling, no liquid nitrogen required.

I had the exact same problem since the last windows 11 patch. My VirtualBox VM's was turteling at around 1/4 of their initial performance. I also noticed that a green turtle has appeared...

The solution was found in the link of scottgus1

In some words :

- Disable Windows Defender's Core Isolation
- pop an admin MS-DOS command prompt
- bcdedit /set hypervisorlaunchtype off
- DISM /Online /Disable-Feature:Microsoft-Hyper-V
- reboot

You made my day !

Glad you're up and running!