Centos running very slow in Virtualbox

Question

I am running Centos 7 in Virtualbox 4.3.14. The VM is configured with

• 2 CPUs
• 4 GB RAM
• 3.10.0-123.4.4.el7.x86_64 kernel

The host machine is running

• Windows 7 Pro SP1 64-bit
• Intel i7-4790 CPU, Hyper-Threading enabled
• 16 GB RAM

Yet, when I start up this VM, it bring my entire system almost to a halt, including my host OS. In Process Explorer of System Internal, I can see all my cores are maxed out by VirtualBox. On my VM using top, the load average is about 2 when the system "idles".

• I have tried the dummy VM trick as per http://tech.shantanugoel.com/2009/07/07/virtualbox-high-cpu-usage-problem-solved.html
• I have tried the divider trick as per https://community.oracle.com/message/9307831
• I have tried disabling "Nested-Paging" as per ... (cannot add more links with my rep)

Previously I used to run a similar configuration using only a laptop with 6 GB of RAM without any problems.

What else can I try to make this VM usable?

Solution

Turns out the physical host machine's CPU fan was never plugged in and because the CPU was overheating, the system slowed down to protect itself.

Comments

[Marcelo]

Could you show what you see when you run top on your guest?

[Jasper Citi]

I cannot. I need more "rep".On the i7 server get a load average of 15.37 (top processes are java processes that take 12.5% - 40.6% each). I copied the same VM to an i5 laptop with only 8 GB RAM and got a load average of 2.28 (top processes are the same java processes that take 17.3% - 17.6% each).

[user]

en.wikipedia.org/wiki/Load_average#Unix-style_load_calculati‌​on