Virtual Ubuntu vs. Lubuntu: Is the difference in performance because of GPU or CPU(s)?

Question

System

• 2x Intel Xeon X5650 @2.67Ghz, 6 cores, 12 threads
• Nvidia Quadro 4000, 2GB GDDR5
• 24GB DDR3
• 240GB SSD
• Windows 10 Pro

Virtual Ubuntu (16.04, 64bit ) having great performance issues

Context

As you can see, I have a beast of a machine running under my table; Total of 12 cores and 24 threads, "decent" amount of RAM and ok GPU, should be more than enought to run any virtual machine without any issues. Wrong.

VirtualBox settings, test 1

• 1 core, accelerations enabled
• 2048Mb of memory
• 128Mb of gpu memory, 3d acceleration enabled

Results

• User experience, very poor. Every desktop action lags very much.
• Watching even 720p videos is impossible.
• Response to typing is very slow.

VirtualBox settings, test 2

• 2 cores, accelerations enabled
• 2048Mb of memory
• 128Mb of gpu memory, 3d accelerations enabled

Results

• The same as previous. Difference to previous very small if none.

VirtualBox settings, test 3

• 4 cores, accelerations enabled
• 4096Mb of memory
• 128Mb of gpu memory, 3d accelerations enabled

Results

• The same as previous two. Difference to previous very small if none.

VirtualBox settings, test 4

• 1 core, no accelerations
• 1024Mb of memory
• 128Mb of gpu memory, 3d accelerations enabled

Results

• The same as previous two. Difference to previous very small if none.

Toughts

It suprises me that dispiting all the different settings, the visible performance didn't change. Even with different screen resolutions. I have this setup running on my other computer (i7, 16gb ddr3, gtx 760@2gb gddr5) and it's smooth sailing all the way. Since that system setup is very different BUT less powerfull by any stats, I think it has to be something about support of my components, gpu or processors. At first I was pretty sure it was because of the gpu, but after the next chapter, I'm not so sure anymore. Keep reading!

Virtual Lubuntu (16.04, 64bit) working just fine

Context

After frustrating tests with Ubuntu, I decided to try Lubuntu, which is much lighter distro, but but basically the same as Ubuntu.

VirtualBox, test 1

• 1 core, accelerations enabled
• 1024Mb of memory
• 128Mb of gpu memory, 3d accelerations enabled

Result

Everything works well, except for the full HD videos (or ones with higher resolution), have a little lag in them. Using the os itself, does work fine and without lagging.

VirtualBox settings, test 2

• 2 cores, accelerations enabled
• 2048Mb of memory
• 128Mb of gpu memory, 3d accelerations enabled

Result

Not much different than previous.

The question

What is causing the poor performance of Ubuntu with my system? Is it CPU, GPU, both or something else? Any ideas?

Answer 1

Check if VT-x, EPT/NPT aka "Nested pages" are enabled in Ubuntu VM.
Don't use guest additions that comes with Ubuntu but re-install it from VirtualBox that you running currently.

Before installing fresh guest additions there should be done some prerequisites(for Debian based distro's ):

You need to install following packages:

dkms
build-essential
linux-headers-generic (On Ubuntu)
linux-headers-{amd64 OR 686-pae OR 486} (On Debian)

by running following command:

  sudo apt-get install dkms build-essential linux-headers-generic

In second step you need to delete pre-installed (usually outdated) guest additions that comes with distro by running following commands:

  sudo apt-get remove virtualbox-* 

Now, mount Guest Addition ISO to the VM. This is done using the Device Menu, then click on Install Guest Additions.

just to be sure that previously installed guest addition removed completely, run from mounted Guest additions CDROM

 sh ./VBoxLinuxAdditions.run uninstall

then run installation of fresh guest additions:

 sh ./VBoxLinuxAdditions.run