Percent CPU allocation

Discussions related to using VirtualBox on Windows hosts.
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whs
Posts: 11
Joined: 8. Nov 2009, 01:15
Primary OS: MS Windows Vista
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: windows7

Percent CPU allocation

Post by whs »

I run Windows7 RC in a vBox partition on a Vista host. I noticed that only 25% of the CPU (Q6600) get allocated to the virtual partition. Is there a way to increase that to e.g. 50%?
MarkCranness
Volunteer
Posts: 875
Joined: 10. Oct 2009, 06:27
Primary OS: MS Windows 7
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: Windows Server 2008 R2; Ubuntu 11.04; Windows 2000 Server; Windows XP

Re: Percent CPU allocation

Post by MarkCranness »

Settings>System>Processor>Processor(s): 2 or more>OK (Section 3.7.2.2 of the manual).

Setting more than 1 processor will also enable System>Motherboard>Enable IO APIC, if it was not already enabled, which will require you to do a Repair Install on Windows 7 so it installs the correct HAL files, and may also trigger re activation required.

People have reported strange performance with multiple CPUs, sometimes with more CPUs processes run slower than with fewer. YMMV.
whs
Posts: 11
Joined: 8. Nov 2009, 01:15
Primary OS: MS Windows Vista
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: windows7

Re: Percent CPU allocation

Post by whs »

Thank you. That was easy and worked perfectly. I set it to 2 (of the 4) processors. All I had to do is reboot.
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