Virtualbox – When 1 CPU is better than 2

The need for speed is never satiable. I was running Windows XP in Virtualbox with 1 VCPU all these while. Speed was acceptable for me to do my office related stuff like Exchange and Office.

My CPU was a Core2Duo with HyperThread. So technically, I have 4 VCPU to play with. So I decided I could spare another 1 core for my Windows XP installation. The result – Terrible.

Windows XP booting took more than 5 mins as compared to about 1.5mins previously. Ran top and saw that Virtualbox was using 198% CPU. Normal circumstances with 1 VCPU, it would be at 98%. Switched back to 1 VCPU, things became normal again.

I’m not too sure if it’s Virtualbox that’s not handling the job scheduling correctly, but if anyone runs into this problem of having slow performance in Virtualbox, this could be the solution.

Author: yibi

YiBi's numb :) YiBi writes about anything. Technology, Gossips, Rubbish YiBi's a half f%#k geek :P


  1. Earlier editions of v3.0 did have some performance issues with multiple CPU’s. I have had better results with v3.1.2. You might want to install the latest, update your guest tools, and try again — 2 CPU configuration should be much improved.

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