Running Windows 8 or Windows 7 on a Mac or a MacBook is simple with virtualisation software, so you need never have to reboot to switch operating systems again. There are three clear options: the open-source and free but limited VirtualBox, or one of the two commercial packages, Parallels Desktop 8 for Mac or VMware Fusion.
Either of the latter are easier to work with than VirtualBox, with broadly similar qualities and very decent performance. We took a closer look at these two powerful applications to see how they compare in their latest respective versions: Parallels 8 and Fusion 5.
Parallels Desktop 8 review
Parallels' core business is running Windows in OS X. Its Desktop 8 software officially supports OS X Mountain Lion, including full-screen mode and the new Retina displays. Notifications now pop up for certain actions, such as when taking a MacBook off mains power. This is noteworthy, since Parallels 8 has a more frugal power mode to ease the battery burden of this processor-intensive software. You can toggle power-saving on a per-VM basis from the Settings panel.
New features include the ability to expand video performance with up to 1GB of video memory. There's support for Windows 8 but, given the Mac's lack of compatible hardware, there's no touchscreen distraction. Parallels is priced at £65, or £35 as an upgrade from the two previous versions. (Read our standalone Parallels Desktop 8 review.)
VMware Fusion 5 review
On its debut, Fusion was well received for its stability and advanced Windows integration. These days, both Fusion and Parallels mix well with Windows, in their Unity and Coherence modes respectively. In Parallels' case, this integration is ironically muddied by an additional Crystal Mode: the difference between the two is not clear.
VMware and Parallels have spent five years vying for dominance, each leapfrogging their rival with new features and increased performance. But Parallels has been working harder, while VMware seems to have ramped down promotion and barely even mentioned this update to the press.
But Fusion 5 is a strong offering, available in two versions: standard (£38) and Professional (£79). The latter is little different, but adds locked-down VMs, restriction settings and can limit access to USB ports. There's also a Network Editor to customise virtual networking.
Parallels Desktop 8 vs VMware Fusion 5: Using the VMs
Parallels' New Virtual Machine wizard makes installing from DVD or disc image easy, or you can create VMs from links to download Ubuntu, Google Android or Chrome OS. You can also migrate Windows from a real PC, or a clean install of Mountain Lion from the Recovery Partition on your Mac. Boot Camp is another choice if you have a partition dedicated to Windows.
Fusion 5 has a larger VM browser that more clearly shows a running machine in a big thumbnail. At a glance you can see how much of the virtual disk is being used by any selected machine.
The two apps differ in their approach to privacy. Whereas Parallels milks social networking, adding Twitter and Facebook links, VMware takes the more sober approach. And it doesn't phone home like Parallels, which does so on every launch to check your registration; it also wants to read your Address Book. Parallels collects data about how you're using it, although this can be switched off.
Both applications now support USB 3.0, although we had mixed results. After installing a Windows driver, we managed to use a Kingston USB drive with both apps, albeit at sub-USB 2.0 speeds. Meanwhile, a LaCie XtremeKey worked at near-native speed in Parallels, but wasn't recognised by Fusion.
In performance terms, Parallels continues its lead over Fusion with consistently faster results in our benchmarks. Using near-matched configurations of Windows 7, two active processor cores and 2GB of memory, Parallels scored 4,305 points in PCMark 7, 8.6 percent faster than Fusion's 3965.
In Geekbench the results were more evenly matched, with Parallels just 3.1 percent faster at 8162 points against Fusion's 7919.
Graphics performance shows the largest difference. Fusion hit a playable 52fps in Stalker: Call of Pripyat, while Parallels added almost a third more frames at 69fps. These results were achieved using a MacBook Pro with nVidia GeForce 650M graphics, 1280x800 resolution and Medium detail.
Other OSes are poorly supported compared to the cash cow that is Windows compatibility. A change in Apple's licensing terms from Lion means you can run non-server OS X inside OS X, but neither Parallels nor Fusion give an experience as polished as Windows VMs.
Hardware graphics acceleration is the notable omission from both apps, meaning jerky screen animations and funky disco rendering of certain elements, such as Safari's Top Sites page. Adobe Flash is unworkable in both, too.
Parallels has other issues with OS X guests, such as the inability to resize VM guest disks. Meanwhile, VMware has poorly configured keyboard shortcuts €“ using Cmd, Q to quit an app in fact closes VMware, for example.
Essential features such as drag-and-drop between host and VM are missing in action for both, and even cut-and-paste support proved to be patchy.
A good reason to run OS X as a VM is for host system security, allowing a relatively sandboxed OS to run exploited software such as Oracle Java. Sadly, current versions of Java won't run on either.
Parallels Desktop 8 vs VMware Fusion 5: Linux
Another great reason for virtualisation is to test and explore desktop Linux systems. This was made trickier in recent years as the familiar distributions now add hardware accelerated video to smooth and enhance the GUI. Both VMware and Parallels can now render these graphics on some popular distros.
We were stalled at our initial attempts to test and review both packages by patchy support of, for example, Ubuntu Linux. As the most popular PC OS after Windows and OS X, it's a handy asset.
In the case of Fusion 5, a new display model has been adapted to allow decent hardware-accelerated graphics for Linux. The update to 5.0.2 caused us problems but 5.0.3 made Ubuntu Linux usable again, with creamy smooth animations.
Both VMware and Parallels are slow to update Linux support when new distros are released. On the eve of the release of Ubuntu 13.04, for example, neither officially support last year's 12.10 yet. See also: How to install Windows 8 on your Mac.