Parallels and VMware have recently updated their virtualization software for the Apple Mac -- both designed to better support Mac OSX 10.7 (aka Lion)

Parallels Desktop is on release 7 and VMWare Fusion is version 4.

As a long-term user of both products I have taken some time to consider, compare and review the various aspects of both.


When Apple launched their new range of Mac's supporting the Intel chipset (rather than the PowerPC and 68k processors) in early 2006 it opened the opportunity to run PC based software (which also runs on the Intel chipset). Initially Apple released the Bootcamp tool which allowed an Apple Mac to reboot and run Windows or Mac OSX.

Very quick to follow this was Parallels virtualization software which would run Windows in a Virtual machine (a window) within OSX, without the need for a reboot. Basically, Windows and OSX were running together. The first Parallels version was released 15 June 2006. VMware followed over a year later with Fusion, released 6 August 2007. Since then both products have been the main focus of Windows virtualization for the Mac.

My usage

I bought both Parallels and Fusion as soon as they were launched -- Sounds strange, but Parallels was the only choice on the market, then when Fusion came along 14 months later I tested it and felt it to be better. Since then (2007) I have jumped between both versions as new releases became available. A few years ago I settled on Fusion release 3 as I was comfortable with it. I also found myself with less need to run Windows apps as the range of Mac apps has increased significantly.

The Review

Now, some years on, I decided the time was right to update to the latest version of either Parallels or Fusion as I have missed several upgrades. Fortunately each vendor offer a free trial of their latest product.

For the test I have attempted to create identical setups: each will run a fully patched version of Windows XP Professional SP3 and the VMs have been configured as follows:

  • Use 2 cores on the Mac Processor
  • 1 Gb ram
  • 3D Graphics enabled
  • Share the MAC network card (NAT)
  • 40Gb disk
  • CD Off
  • Audio On

Any other settings are left as per the default installation of the VM software. The testing was run on an Apple iMac 2.5Ghz quad Core i5 with 4Gb Ram, running on OSX 10.7.1

First of all, some data..

Some comments:

  • Startup -- the app was already loaded; the time is the number of seconds from starting the VM to the Windows Login prompt
  • 'VM memory used' is the amount of memory consumed by the VM just after Windows had loaded.
  • 'Mac App Memory' is how much memory the actual native Mac application consumes
  • 'VM Diskspace' is the size of the Virtual Machine file in the Mac file system

General Observations

Fusion took considerably longer to startup/shutdown the Windows O/S. It also consumed far more of the Mac's native resources. Each VM was assigned 1Gb of memory and Fusion very quickly consumed all of this. Parallels on the other hand seemed to manage memory better and I had to work hard to get it to consume a full 1Gb.

Similarly the actual size of the file for the VM within the Mac file system was quite different. Each were assigned a 40Gb maximum and each will start low and grow the file size as needed. Fusion was using 25Gb of disk space and Parallels far less at 16Gb. Remember both are using an identical Windows setup so I was not clear why Fusion was taking so much more. Fusion was actually using 29Gb but you can ask it to compress, which dropped it slightly.

Fusion did use less memory for the native Mac app but this small saving was eclipsed by the greater overall resources it consumed.

Performance in Windows

Once loaded each VM ran very well and almost identical performance was noted. I loaded a variety of windows apps (including Word, Excel, Outlook, Internet Explorer, Firefox, Open Office, iTunes for Windows, Google Picasa, and a few other imaging apps). The load times were near identical so I felt no need to list them all here.

Each VM can operate in several modes: full screen; a single window app; Unity/Coherence mode (the ability to make a Windows app look like it is running natively in OSX)


Although they both perform very well once loaded, for me the clear winner is Parallels 7. When I need to access a Windows app I want to fire it up quickly and get to the application. Fusion was noticeably slower at startup and shutdown. Parallels in Coherence mode was less visually appealing than Fusion's equivalent (Unity mode) -- when you dragged a window around you get a noticeable shadow and lag in Parallels; this is really a minor thing and only if you are using Coherence.

Overall Parallels looked better and seemed simpler to configure. I have no doubt I could have spent time tweaking the settings of Fusion/Parallels to improve performance but I felt the config was a true reflection of how the masses would use it (out of the box config).

I was surprised in my finding as I have been a happy Fusion user for years. What this does demonstrate is that loyalty is perhaps foolish and we should always be prepared to review alternatives periodically.

Have you used either? What are your thoughts?

Parallels Desktop is available for £65 full price/£35 upgrade. VMWare Fusion is available for £35 for a limited time, after which it will be £60. There is not upgrade price.

Each offer a fully functional trial version.

Parallels also offer a competitive upgrade to existing Fusion customers ...

If you are looking for a very detailed review I thoroughly recommend the one over at Ars Technica.  A very long read but brilliant detail.

site by DAJ