virtualbox.org

hello,

Running a windows 10 guest (on a windows 10 host) and for some reason I have not been able to figure out the same guest is sometimes smooth/normal and sometimes really slow.
This slowness is best visible when switching between windows in the guest, redrawing is really slow, you see a black window before you it getting filled in.
It gets worse (slower) over time.

However the interesting part is that shutting down the guest and starting it again solves it most of the time (about 90/10)
The client is not running anything else then VirtualBox.
This only happen with the windows guest, a linux guest always runs smooth.

recap:

start laptop -> start windows 10 guest -> 50/50 change it's smooth, if not -> shutdown windows 10 guest -> start windows 10 guest -> smooth
Waiting longer after start laptop does not make a diffrence

I have included a log file of both situations, might be interesting.

Your host CPU only has 4 physical cores.
Please try running your guest with only 2 or 3 virtual CPUs so that the host has at least one core "free" to handle running the guest / Virtualbox.

The only statistic that caught my eyes were the bytes received from the network: The fast run received 178 MB in over 8 hours, while the slow run received 947 MB in 48 minutes. Windows updates maybe?

The statistics would be easier to compare, if both runs were approximately equally long, BTW.

hi Martin and fth0

it seems to have been the 4 CPU's, having it on 3 for last 2 days and so far no issue.
I read the cpu slider wrong in VB, I though it was nr of HT since the slider goes to 8 (4x2) and stays in the green at 4. But seems its 4 cores.

Thanks for your help.

akm-gh wrote:I read the cpu slider wrong in VB, I though it was nr of HT since the slider goes to 8 (4x2) and stays in the green at 4. But seems its 4 cores.

The slider shows neither CPU cores nor hyperthreads, but the number of virtual CPUs you provide to the VM. In general, it makes sense to split up your CPU cores between the host and the (simultaneously running) guests, two vCPUs per VM usually being the best.