PRODUCT REVIEW
Parallels 4.0 Not Quite Fully Baked

It instantly became the de facto standard for breaking down walls between operating systems on the Mac OS.

Parallels uses a technique called "virtualization," which creates a virtual computer running within the physical, real computer. Called a "virtual machine," it can use different operating systems, allowing Mac users to simultaneously run, say, Windows or Linux . (There's also a Windows version of Parallels, though you can't use it to run the Mac OS X on a Windows PC.)

Parallels Swings Back

Parallels has since drawn competition on two fronts. VMware (NYSE: VMW), the leader in virtualization software for businesses, released a Mac product called "VMware Fusion," which is at version 2.0. There's also a free, open source product, VirtualBox, which Sun Microsystems (Nasdaq: JAVA) is aggressively developing.

For a while, as VMware grabbed market share and VirtualBox earned a reputation as worthy freeware, Parallels Desktop was missing in action. Version 3.0 was released in mid-2007 and has had only a few maintenance updates since.

Then, earlier this month, a new version was released, almost out of the blue. Parallels Desktop for Mac 4.0 underwent private testing, but unlike 3.0, the public didn't get a chance to bang on it in an open beta. And that's a shame, because there are serious issues with this new version that probably could have been ironed out if more folks had been able to test it.

Rough Around the Edges

While version 4.0 is an excellent product -- it leapfrogs VMware Fusion 2.0 in terms of features -- it's quite rough. There are some particularly thorny problems with the way the new version upgrades virtual machines that were created using the previous version.

Parallels Desktop 4.0 runs only on Intel-based Macs. Like previous versions, it lets you work in a window on the Mac desktop; in full-screen mode, as though you are working on a standard Windows PC; or in Coherence mode, in which the Windows desktop vanishes and Windows applications float freely on the Mac desktop. This is my favorite way to work -- basically, it renders the operating system moot.

Version 4.0 adds a new mode, Modality, which turns a VM's display into a small, resizable, transparent window. This is great if you're on a notebook and want to work with a Windows VM, but don't have much screen real estate. You can do anything in the small window that you can in the other modes -- launch programs, move windows, copy/paste.

Less Resources Used

The overall design is much more Mac-like -- in fact, it looks like VMware Fusion 2.0. It retains one of the features that I love about Parallels -- the ability to pause the virtual machine. VMware Fusion still doesn't have this feature.

Version 4.0 now adds better 3-D graphics, catching up with VMware Fusion 2.0 by supporting Microsoft's (Nasdaq: MSFT) DirectX 9.0. It also adds support for OpenGL 2.1, making it OK for casual gaming. However, neither Fusion or Parallels yet supports the glass feature in Windows Vista's Aero interface.

It also uses fewer resources. Parallels has been known as a processor hog, bogging down the CPU. But this new version is light on the throttle, usually using well under 10 percent when idling in my tests.

One of my favorite new features in Parallels 4.0 fixes a longstanding problem in most virtualization programs.

Usually, the CD or DVD drive on a computer can only be accessed by the host or guest operating systems, but not by both at the same time. Parallels Desktop 4.0's new SmartMount lets you do this. Let's say you have photo files on a CD -- you can access them with Photoshop on the Mac and with Paint Shop Pro on the PC interchangeably -- no need to mount or unmount the drive for the guest and host operating systems.

Wait for a Patch

However, if you choose to upgrade from Parallels Desktop 3.0 to 4.0, be warned that the process has some serious bugs.

The program must convert your VMs to the new 4.0 format, and I got several error messages warning that the conversion had failed. I kept clicking through these messages, and eventually the process completed, but not without manual configuring.

Parallels' forums are filled with cries of anguish from those who weren't so lucky. While I like this new version, I'd recommend you avoid it initially if you're a 3.0 user. Wait for the first patch before making the leap. The new features are worth it, but not at the cost of nuking your existing virtual machines.