When Apple moved its hardware to Intel processors in 2006, using Windows on a Mac became a practicable reality. Virtualisation packages followed, allowing you to run Windows inside Mac OS X without having to reboot into a separate partition. Parallels was the first, and now in its latest Parallels Desktop 4.0 guise, it's a fully featured and mature program.
There are three such virtualisation programs on the market, if you include the free open-source VirtualBox, but the leaders are Parallels Desktop for Mac and VMware Fusion. These offer almost identical features and now even sell for the same price of £49 - but Parallels Desktop 4.0 adds new options that sees it just nudge ahead of Fusion 2.0.
With a virtual machine (VM) running - typically Windows, but Linux and other x86 OSes are supported - you can opt to see a traditional windowed version of the system desktop; or in Coherence mode where open apps appear mixed together on the Mac desktop. Parallels Desktop 4.0 has now added a Modality mode which reduces a VM to a small thumbnail, making it easy to oversee many running VMs. Catching up with Fusion, Parallel's guest OSes can now be 64-bit, and multi processors are also supported.
SmartGuard is Parallels Desktop 4.0's technology for taking automatic snapshots of the state of a virtual machine, allowing easy rollbacks in the event of problems. Once installed on a Mac, Parallels automatically takes over the opening of Windows programs, so that all .exe files on a Mac carry the Parallels icon. Where Fusion comes with McAfee antivirus to help tame Windows malware, Parallels now comes with AV and backup software from Russian countrymen Kasperksy and Acronis.
Aside from features that increase integration between the VM and the Mac host, such as showing open apps in the OS X dock or accessing a shared Mac DVD drive in Windows, Parallels Desktop boasts that the latest version 4.0 is faster and has better graphics capabilities too.
To see just how fast, we compared Parallels Desktop 4.0's performance against the latest VMWare Fusion 2. We used our standard WorldBench 6 real-world test suite on the same configuration of Microsoft Windows XP Professional SP3, followed with our graphics test of FEAR at Maximum quality settings. Using an Apple MacBook Pro 2.4GHz, both setups used a 20GB fixed-size virtual disk, set to 1GB RAM and the maximum amount of video RAM - 128MB for Fusion, and 256MB for Parallels.
The scores were very close indeed, with Fusion 2.0.1 achieving 77 points in WorldBench, and Parallels 4.0, 79 points. In FEAR, both Fusion and Parallels hit an average framerate of 19fps - although Parallels was visible smoother and had fewer visual artefacts. It's worth noting that these are impressive gaming scores for a virtual graphics adaptor, as many PCs we see using real graphics chips struggle to get above 4fps in this test.