Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When I run VirtualBox (or other virtualisation software) it lets me select how many cores I like to allocate to a virtual machine.

Since I have a dual core 2.66gHz Intel Core i7 with hyperthreading, would I be assigning "cores" in VirtualBox from the four threads that the i7 provides, or only from the two physical cores?


share|improve this question
up vote 0 down vote accepted

VirtualBox is the worst when it comes to multi cores/cpu. If you REALLY need multi cores, use VMware. (Even Player can create Guests). Virtualbox is only ok with one core, since you have to enable IO APIC which will make the guest sooo slow it doesn't worth it.

share|improve this answer
Any benchmarks that confirms your statement? – liori May 22 '10 at 19:40
OK. So will VMware recognise my four threads as core OR will it only recognise the two physical cores in my i7? – hpy May 22 '10 at 19:42
You can assign CPUs and cores. You can assign 8 cores, 16 cores. Since you don't have two CPU. ^^" (In short: yes it will.) – Shiki May 23 '10 at 5:42
This answer is not true anymore. VirtualBox has support for I/O APIC now, and runs great with multiple cores. – FrederikNS Dec 6 '13 at 8:26
@FrederikNS: The IO/APIC support was terrible. Well, even now it is. If you add some load to the host, the guest will be terribly slow with IO/APIC. This is not happening with VMware, which remains rock solid. I mean, heck Virtualbox is not "free", it's an Oracle product. VMware is a product is well. X is better than Y, and that's it. Just use the Player version of VMware, and be happy. – Shiki Dec 6 '13 at 19:41

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .