Ubuntu runs very slowly inside of VirtualBox.

How do I run Ubuntu with unity or enabled transparency smoothly with VirtualBox?


2 Answers 2


Graphic/performance fix for Ubuntu was tested with Ubuntu 13.04, 12.10, and 12.04. Part of this solution applies where aero / transperancy is used including d3d games.

RAM requirements

Recommended graphic memory or virtual ram for aero based operating systems is 256 MB min.ram -768 MB for 13.04

Virtual machine settings

  1. enable 3d support in virtualbox 3d settings

  2. terminal commands:

    /usr/lib/nux/unity_support_test -p 

    (Not software rendered:no, unity 3d support:No)

    uname -r
    sudo apt-get install linux-headers-$(uname -r)
    sudo apt-get autoremove
    sudo apt-get install build-essential

    now insert vitualbox guest iso from devices and to install manually follow

    cd /media
    cd username
    cd VBOX*
    sudo ./VBoxLinuxAdditions.run
    sudo gedit /etc/modules

    add "vboxvideo" in the next line after lp means loop>lp>vboxvideo like this click save and file quit

  3. restart the machine

  4. now open the terminal to checkunity 3d is enabled or not

    /usr/lib/nux/unity_support_test -p
  5. after this shut down the machine lets increase the virtual ram

  6. close virtual machine and virtual box

  7. follow this path C:\Users\Username\VirtualBox VMs\ubuntu 13.04

  8. now look for ".vbox" extension file and open it with temporarily with wordpad

  9. look for the following lines and replace these in following manner

    Display VRAMSize="128" monitorCount="1" accelerate3D="true" accelerate2DVideo="false"/>


    Display VRAMSize="256" monitorCount="1" accelerate3D="true" accelerate2DVideo="false"/>
  10. now you can set 256 mb virtual memory for this operating system.

  11. any OS can be provided with desired vram this way

Reference and sources::

babarehner @ e-wrench.com and youtube

sanct on http://ubuntuforums.org/forum.php

rpxmac on forums.virtualbox.org

Related questions on Ask Ubuntu

How do I install Guest Additions in a VirtualBox VM?
How do I enable hardware virtualization technology (VT-x) for use in Virtualbox?
Ubuntu installation in VirtualBox - not using base memory in RAM

  • 3
    FYI, you can change those VRAM and other settings through the VirtualBox UI now.
    – ashes999
    Aug 19, 2014 at 14:07
  • Can't find VBoxLinuxAdditions.run anywhere? Nov 28, 2015 at 11:53
  • 2
    @ashes999 But only to 128MB
    – Sebi2020
    Oct 27, 2017 at 21:09
  • Failed to open a session for the virtual machine kali linux. VRamSize is too large, 0x20000000, max 0x10000000 (VERR_INVALID_PARAMETER). Result Code: NS_ERROR_FAILURE (0x80004005) Component: ConsoleWrap Interface: IConsole {} This isn't working.
    – Ashim
    May 20, 2021 at 17:33

Make sure you enable 3D support on Virtualbox, and on guest Ubuntu virtualbox setting. Also give your virualbox enough RAM and cpu cores. Having dedicated VGA will help virtualbox performance as well. How to fix slow performance ubuntu 13.04 running in virtualbox


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