virtualbox.org

I'm quite new to virtualbox and installed virtualbox for the first time.

I realized, that virtualbox uses around 50% of my host cpu if the guest is idle (to be honest the guest, which is vista 32 bit, is around 5%).
If the guest is around 100% cpu usage, the host cpu usage stays constantly around 60 %. Hhhhmmm!!??

My host is a windows server 2003 64 bit and I've an intel dualcore cpu.

I read some posts here about that issue but didn't get any solution.


Any ideas?

Do you have I/O APIC enabled in the VM settings? Unless you run a 64 bit guest, you might want to disable it and see how that goes. It was discussed here a few topics down, though with a different Host and Guest, but same result.

Yes, I read that discussion, but I/O APIC was disabled by default.
I also tried to set the process affinity (in my case it's virtualbox.exe) to only one cpu - that didn't change anything.

I've the same problem with Phenom 9600 Quad Core and 4GB memory. I'm running Vista 64-bit host and having the same problem with both XP and Vista 32-bit guest. The guest CPU is at 100% while the host CPU is at 30%. I've problem with VirtualBox version 2.04 and the previous versions.

The IO APIC is disabled. ACPI and VT-X/AMD-V are enbled. Could this problem be related to the TLB bug associated with the Phenom 9600.

Thank you for your response.

I had the same problem but solved it. Try disabling USB for the virtual machine. You can also try only disabling EHCI (USB 2.0).
My system is an AMD X2 CPU, 4 GB RAM, XP Pro x64, and OpenSolaris as the guest.

http://forums.virtualbox.org/viewtopic.php?t=11668
http://forums.virtualbox.org/viewtopic.php?t=262

Joined: 17 Mar 2008
Posts: 3823
Location: Netherlands
Posted: Mon Nov 24, 2008 4:08 pm Post subject:

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VB will use only one CPU at max for one VM. The Host can swap it's processing to either core, or distribute it over several cores. It will never go above the total use of one core.