Did you know you can download and run any version of Windows in VirtualBox for free?
Upgrade the memory
When a guest operating system is running in a virtual machine, it uses a lot of memory. This mean that there is less left for Windows to run.
It is very difficult to run VirtualBox with virtual machines on a Windows PC with just 4GB of memory. It can be done, but both Windows and the guest OS in VirtualBox will run very slowly.
This is because it is constantly reading and writing to the page file, which is used as an extension to system memory. It is a zillion times slower though.
To run virtual machines you need at least 8 GB of RAM in your PC. It is the bare minimum and 16 GB is recommended. This enables you to allocate a decent amount of memory to the virtual machine and still have plenty left to run Windows.
Buy more RAM!
Allocate more memory
If you have lots of RAM in your PC, you can increase the amount that a virtual machine uses.
The more memory that a guest operating system has, the faster it will run, so if you can allocate 4 GB of memory to the virtual machine it will run much faster than if it has only 2 GB.
- Select the virtual machine in the list and click Settings in the toolbar.
- Select System and select the Motherboard tab.
- Drag the slider further to the right, but avoid the red area because this will slow down the computer because it could run short of memory.
Allocate more processors
A computer with a 4-core CPU is faster than one with a 2-core CPU (all other things being equal), so giving the virtual machine more processors will speed it up.
The number that can be allocated will depend on the CPU in your computer. If you have an Intel Core i7 for example, you have more cores to allocate than with a Core i3.
- Select a virtual machine and click Settings in the toolbar.
- Select System and then the Processor tab.
- Drag the Processors slider up to the point where green turns to red. This means the computer is allocated half the CPU cores and the virtual machine is allocated half of them.
If you cannot drag the slider past 1 CPU, the fix is here: The one BIOS tweak you need to boost VirtualBox speed.
Set the Execution Cap to 100%.
Increase the screen memory
The screen display is generated by the graphics hardware and the more memory it has, the faster it runs. Increasing it can help to speed up the Linux or Windows virtual machine.
- Select Display and select the Screen tab.
- Drag the Video Memory slider all the way to the right.
- Enable the acceleration options.
Install Guest Additions
Guest Additions is a set of drivers that replace Windows defaults and they speed up the virtual machine enormously. Especially the screen display, which is about 10 times faster with the Guest Additions.
- Start the virtual machine.
- Go to the Devices menu and select Insert Guest Additions CD image.
- If you are running Windows in the virtual machine, open Explorer, open the CD/DVD Drive and run VBoxWindowsAdditions.
- If you are running Linux, open a Terminal window, change to the directory where the CD/DVD drive is mounted, and enter sudo sh ./VBoxLinuxAdditions.run
Change the power plan
The power plan that Windows is using affects the speed at which Windows or Linux runs in a virtual machine. As I described in Speed up VirtualBox with this one tweak, switching power plans makes a huge performance difference.
- Right click the battery/power icon at the right side of the taskbar and select Power Options.
- Expand the lower section if necessary (there is a little down arrow on the right), and select the High performance power plan. You will be amazed at the difference it can make.
Upgrade to an SSD
Old style mechanical disk drives are very slow compared to solid state drives (SSDs). Virtual machines use the disk a lot and if you have an SSD then the guest OS and the host computer will both perform much better.
If you can afford it, consider upgrading the hard disk drive to an SSD.
Other ways to speed up VirtualBox
If the PC has only 4 GB of memory it is best to reduce the memory used by the virtual machine to a minimum. Both Windows and Linux will run with 1 GB of memory. Select the virtual machine, go to Settings, System, Motherboard and reduce the memory to 1 GB.
Go to Settings, Display and drag the Video Memory slider down to the start of the green area.
These settings are not the optimum for a PC with 8 or 16 GB of RAM, but they are best for a PC with only 4 GB of RAM.