What is Hardware Virtualization?

Hardware virtualization is a system which uses one processor to act as if it were several different computers. This has two main purposes. One is to run different operating systems on the same hardware. The other is to allow more than one user to use the processor at the same time. While there are both logistical and financial benefits to hardware virtualization, there are still some practical limitations.

The name hardware virtualization is used to cover a range of similar technologies carrying out the same basic function. Strictly speaking, it should be called hardware-assisted virtualization. This is because the processor itself carries out some of the virtualization work. This is in contrast to techniques which are solely software based.

Both the major processor, or "chip," manufacturers have their own hardware virtualization set-ups. Intel's is known as Intel® VT or IVT. Advanced Micro Devices' system is known as AMD-V™. Other names used include accelerated virtualization, hardware virtual machine or native virtualization.

The primary use of hardware virtualization is to allow multiple users to access the processor. This means that each user can have a separate monitor, keyboard and mouse and run his or her operating system independently. As far as the user is concerned, they will effectively be running their own computer. This set-up can cut costs considerably as multiple users can share the same core hardware.

Somebody accessing a computer through hardware virtualization may be said to be running a virtual desktop. There is a risk that this may cause confusion. That is because the phrase virtual desktop is also used to describe features in some operating systems which allow the user to effectively expand their on-screen desktop beyond the visible area on their screen.

There are some significant limitations to hardware virtualization. One is that it still requires dedicated software to carry out the virtualization, which can bring additional costs. Another is that, depending on the way the virtualization is carried out, it may not be as easy to add in extra processing power later on as and when it is needed.

Perhaps the biggest drawback is that no matter how efficiently the virtualization is carried out, the maximum processing power of the chip cannot be exceeded. This means it must be split between the different users. Whether this is a problem depends on what type of applications they are running: the system is better suited to activities such as web browsing and word processing than activities such as video editing which eat up more processor power.