Mac virtualization face-off: VMware Fusion 4 vs. Parallels Desktop 7

InfoWorld - In the Mac-based desktop virtualization world, there are two significant choices: Parallels Desktop and VMware Fusion. Both have been updated to take advantage of Mac OS X Lion. In addition to supporting Lion as a host, both take advantage of Apple's change in policy that lets users run the desktop version of Mac OS X Lion in virtual machines. Prior to Lion, Apple restricted such usage to Mac OS X Server. Both Parallels and Fusion of course run various versions of Windows and Linux, their primary use case.

As our review of Parallels Desktop 7 noted, there's not much compellingly new to that product since its last update, a year earlier. Does VMware Fusion 4.01 up the ante in any significant way? Not really. Just as Parallels Desktop 6 runs fine on Mac OS X Lion, so does VMware Fusion 3.1; the main reason to upgrade to Fusion 4.01 is to gain the ability to run Mac desktop VMs, a handy feature if you're a Mac developer or tester.

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I disliked the difficulty of installing Mac OS X Lion in Parallels Desktop 7; the software assumes you don't have a local copy and thus defaults to re-downloading the whole 4GB image file. If you've already downloaded the Lion installer image, Parallels makes you jump through arcane hoops to use it. That's not the case with Fusion 4.01, which works with the Install Mac OS X Lion.app installer file just as easily as it does with a Windows or Linux .iso file -- that is, easily. Ironically, what Fusion won't do is connect you to the Mac App Store to download a fresh copy of the installer, as Parallels Desktop does. You need to get it yourself, which is not at all difficult. But it shows that Parallels assumed newbie users, whereas VMware assumed more technical Mac users.

Like Parallels Desktop, Fusion can't install Mac OS X from an existing partition, a Time Machine backup, or a disk image. And like Parallels Desktop, Fusion doesn't see FireWire or Thunderbolt drives, so once you're running the Mac installer or Lion itself in a VM, you can't use the migration tools that Apple provides for such transfers. Because most FireWire and Thunderbolt drives also have USB ports, you can switch buses for that migration, then go back to the speedier bus for everyday operations. Just note this means you can't back up your Mac VM separately via Time Machine if you don't have a USB drive for that purpose.

So, VMware Fusion and Parallels Desktop are equivalent in their Mac VM support, save for their installation differences.

They're also close in their performance, though Parallels Desktop 7 outscores Fusion 4.01 in the PassMark suite of Windows benchmarks, running 9.5% faster overall. (I tested both on an early-2011 MacBook Pro with 8GB of RAM and a 2.0GHz Intel Core i7 running Mac OS X 10.7.1 Lion with the VMs on a FireWire 800-connected 500GB external drive.) When it gets down to specific performance aspects, they differ strongly. Parallels Desktop is much faster (63.3%) for CPU operations than Fusion, but Fusion sigificantly outperforms Parallels Desktop in all the other categories: 2D graphics (by 32.5%), 3D graphics (by 53.3%), memory (by 17.9%), and disk (by 7.7%), as the table below shows.