An Overview of Desktop Virtualization Products

They say you get what you pay for; however, in terms of desktop virtualization products, you can get a lot of value from the free products that are available. Although these products don’t offer anywhere near the same feature set as VMware Workstation, they are all very capable and most of them are free.

Parallels Desktop 4 for Windows & Linux

Parallels plays primarily in the desktop virtualization space with its Mac product, Parallels Desktop for Mac. Lagging behind the flagship Mac version is its Windows version, Parallels Desktop 4 for Windows & Linux, which runs on either x86 or x64 platforms. Unlike the other desktop virtualization products in this sidebar, Parallels Desktop 4 for Windows & Linux isn't free: The product retails for $79.

For the price, the product does offer several cool features. On the technological side it supports VMs with up to eight virtual CPUs and up to 8GB of RAM per VM. It provides USB support for VMs and can take advantage of Intel-VT or AMD-V hardware virtualization if present. Parallels Desktop brings the Convergence feature to Windows, which essentially lets you seamlessly integrate VM applications with your Windows desktop similar to Windows 7 XP Mode. You can download a free trial of Parallels Desktop for Windows & Linux at the Parallels website.

Parallels is currently working on a new version of Parallels Desktop for Windows & Linux, which should be out about the time this review is published. In addition, Parallels also offers the Parallels Workstation 4.0 Extreme desktop virtualization product. Like VMware Workstation 7.0, Parallels Workstation 4.0 Extreme provides support for 3D graphics. It supports up to 16 virtual CPUs per VM and up to 64GB of RAM per VM.

The current version requires the Intel Xeon 5500 processor and NVIDIA Quadro FX graphics card with SLI-MOS technology. Parallels Workstation 4.0 Extreme costs $399. You can find out more about it at Parallels.com.

Microsoft Virtual PC 2007 and Windows Virtual PC

Now getting long in the tooth, Microsoft’s Virtual PC 2007 is more than three years old, which is like a millennia in the fast-moving virtualization market. When you combine that with the fact that this product was never close to being the technological leader in this space, well, you get the idea. Still the product does provide basic desktop virtualization for Windows-based VMs. Supported guests are limited to Windows.

Linux will run but it has no Linux VM integration components and Linux isn't officially supported. Virtual PC 2007 supports x86 and x64 hosts. There is no x64 guest support, but it does support a single virtual CPU. VMs can access up to 3.6GB of RAM. It offers good multiple monitor support but no USB support in the VMs.

Although Microsoft has essentially put Virtual PC 2007 out to pasture, it’s the technology behind a couple of other Microsoft virtualization technology including the Med-V product which is part of the Microsoft Desktop Optimization Pack (MDOP) and the new Windows Virtual PC for Windows 7. Virtual PC 2007 is free and can be downloaded at Microsoft’s website.

Windows Virtual PC is the successor to Virtual PC 2007. It runs only on Windows 7, and it supports both x86 and x64 hardware. It offers several important improvements over Virtual PC 2007 including support for USB ports, support for Windows XP Mode—which allows seamless running of VM applications from a Windows 7 desktop—and integration with Windows Explorer for VM management, support for multiple threads, and host printer access for VMs. Like Virtual PC 2007, Windows Virtual PC lacks support for 64 bit guest OSs, and it’s limited to one virtual CPU and 3.6GB of RAM per VM.

Windows Virtual PC is an improvement over Virtual PC 2007, but its main purpose is really to support Windows XP Mode in Windows 7. Windows Virtual PC is a prerequisite for Windows XP Mode and is a separate download. If you’re confused about Virtual PC 2007 and Windows Virtual PC, just remember that Virtual PC 2007 is for Vista and earlier, while Windows Virtual PC is for Windows 7. You can get Windows Virtual PC from Microsoft's website.

VMware Player 3.0

Another VMware product in the desktop virtualization space is the free VMware Player product. Previously, VMware Player was able to run only existing VMs and couldn’t be used to create new VMs. That’s no longer the case: VMware Player 3.0 is completely capable of creating VMs as well as running them. Player 3.0 runs on both x86 and x64 hardware and supports most Windows and Linux OSs for the host and in the guest VMs. Player supports VMs with four virtual processors and up to 32GB of RAM per VM. However, as you would expect, it lacks the high-end features found in VMware’s Workstation product. For instance, Player doesn’t support clones, snapshots, or VM recording. VMware Player 3.0 is free and can be downloaded at VMware’s website.

Oracle VirtualBox 3.2

If you’re immersed in the Windows world, you might not be familiar with the other major player in the desktop virtualization market: Oracle’s VirtualBox (formerly Sun’s VirtualBox). VirtualBox runs on x86 and x64 hardware and has the broadest host OS support of any of the desktop virtualization products. VirtualBox runs on Windows, Linux, Mac, and OpenSolaris. It provides support for VMs with up to 32 virtual CPUs and up to 1.5GB of RAM per VM on a 32-bit Windows host. This limit doesn’t apply to 64-bit hosts.

VirtualBox provides a virtual USB controller enabling you to connect to physical USB devices on the host for your VMs. It also provides built-in support for up to eight monitors. One unique feature in VirtualBox is its support for teleportation, which is like live migration. Teleportation enables you to move VMs between hosts with no downtime for the VM. VirtualBox 3.2 is free and can be downloaded from the Internet.