virtualbox.org

Hi all,

I'm running Ubuntu 64 on Windows 10. I've been using it successfully for a couple of years. After the last VirtualBox update, my VM runs very slowly, almost like it's being throttled or something. Processes are noticeably slower and performance of even simple bash tasks are very slow when multitasking.

Any ideas why I might have experienced this sudden performance regression? I've attached a log...

JS

Well, one thing I notice is that the graphics RAM allocation is ridiculously low. I'm amazed this ever worked. Increase to 128MB and enable 3D acceleration.

Also, is your VM crunching a lot of numbers? If not, try it with fewer CPU cores (2 is normally good).

Hi, I can try those things. But I don't use any kind of windowing or GUI, it's all just headless console output. Yes, it's pretty CPU heavy... I did reduce the number of cores from 6 to 4. Did not help.

After the last VirtualBox update

What was the previous version? The above log has your Virtualbox at 6.1.8.

Joshuas wrote:I did reduce the number of cores from 6 to 4

The log shows the guest already at 4. Reduce to 2 for a test, as Mpack suggests.

If you downgrade back to the previous version, does the guest performance at 4 or 6 cores return?

The above log was taken while the guest Virtualbox window was still open, thus missing some diagnostic data. Logs are more helpful when the guest Virtualbox window has been closed first.

Here is that log with a full power on/power off cycle. Processors reduced to 2, video memory increased to 128mb and 3d acceleration turned on. I don't know what previous version I was on, but I tend to try to keep it up to date and apply updates frequently.

Still experiencing poor performance... really appreciate any insight anyone can provide.

Check System > Acceleration > Enable Nested Paging. It is essential for a decent virtualization performance.