VirtualBox CPU usage 100% on host [closed]

I have installed VirtualBox 3.1.2 (latest) on my Windows 7 (x64). In the VirtualBox I've installed Windows 7 (x64). I have 4 GB RAM installed. The guest has been assigned a 1536 MB RAM. Sometimes the CPU usage on the host goes 100%.

It happens everytime, in a few minutes, after starting the guest. Then it stops responding. Then I have to "power off the machine" from the menu without doing a proper shutdown. It happens with Windows XP as guest too (even when the RAM amount assigned to it was the same). What is the problem?

The following has completely solved the problem for me :

Your CPU will, by default, prompt Windows to load the ACPI-enabled SMP kernel. So when you switch to having Windows virtualized, this kernel remains and uses some ACPI registers that have severe virtualzation penalties (it talks to the BIOS).

The solution is to force Windows to stop doing that. You can do this by going to Device Manager (right click on My Computer -> Hardware -> Device Manager), expanding ‘Comptuer’, right-clicking ‘ACPI Multiprocessor PC’, select ‘Update Driver…’, choose manual installation, from a list, and select ‘Standard PC’.

Then reboot your guest VM.

the CPU is not virtualized, obviously the guest OS is performing some CPU-intensive task(s) after the start which subsequently affects the host.

you should tweak the guest OS (disable unnecessary services and programs).

Since I didn't get any help here nor on the other sites, I checked for other VirtualBox alternatives and came across VMWare. Its performance is really great! Plus I get to see the Windows aero style activated on VMWare! I immediately switched. Deleted the old VMs as they had to be converted from vdi to vmx. I didn't want to take all the trouble.

Currently I have installed VMWare Player which is FREE! It has Windows 7 as guest with aero activated and it works fine. Hope VirtualBox gets improved so that I could sswitch back. But not before they add aero support!