Virtualisation or Virtual Machine technology allows you to run one operating system inside another, for example, Windows XP inside Mac OS X. There are many reasons why this is desirable, but most users simply want the ability to run their choice of operating system and still have access to software that runs on other systems.
Virtualisation technology is nothing new. Running a guest operating system inside a host has been possible for decades, but whats been missing from the technology up until now is speed. With the recent release of virtualisation enhanced processors and sophisticated software, most speed problems are a thing of the past.
The principle benefits of virtualisation stem from its portability. An entire virtual machine exists as a single file on the host systems disk drive. This makes backing the whole thing up fast and very easy, and means that the entire system can be transported to another host with very little downtime. Any system that can run the virtual machine software can serve as a host.
Sandboxing And Rollback
A virtual machine offers a great sandbox for trying out new software (or indeed development and support). Some are even using virtualisation to facilitate safer Internet browsing. If the system is compromised, you can restore to the last backup in a matter of seconds with no harm done to your host system.
You can also maintain point-in-time snapshots of virtual machines and run multiple copies, simultaneously if you like.
While virtualisation products have existed for Windows and Linux operating systems for some time, Mac solutions only began appearing after Apples recent switch to the Intel processor platform.
VMWare have long been the leaders in virtualisation and they have patented the snapshot ability, where a virtual machine can be backed up very quickly without interruption. This makes VMWare the choice for those wishing to run servers virtually.
Those wishing to run different or multiple operating systems on their desktop have a new choice in Parallels Desktop. This was the first product to take advantage of new hardware virtualisation features in modern processors, and the first to be offered for use on Intel based Mac systems.
Parallels Desktop for Mac allows you to run any PC operating system on a Mac, and does a particularly good job with Windows XP.
This product has received widespread acclaim since it was first released as a public beta. Despite being shipped as a stable, finished product, development continues at a frenetic pace. Significant recent additions include the ability to create a virtual machine from an existing Windows installation and Coherance, the name given to a new feature that allows Windows applications to be run directly from the Mac OS X desktop.
Because of the beta status of VMWare Fusion, it would not be fair to compare the product with Parallels Mac offering at this point. I have instead compared the performance of running Windows natively, versus inside Parallels on the same computer.
I was surprised when benchmarking to discover that the Parallels virtual machine does some things, particularly disk and network access, even faster than Windows XP natively! As a result, most business applications will run considerably faster using Parallels on a Mac than they do on a Windows PC.
Benchmark 1: System Level Tests
I first used Passmark softwares benchmarking tool to compare the performance of Windows running on Parallels with Windows running natively using BootCamp on the same Mac. The following graph highlights the stunning results:
Network speed was calculated using the average of small, medium and large FTP downloads.
As you can see, both disk and network performance are nearly twice as good under Parallels. 2D graphics are a little better, memory a little worse. Im not certain that the CPU comparison is accurate as I suspect Passmark may not be measuring the Macs dual-core processor properly when running virtualised.
Benchmark 2: Medical Director 2
The next tests were done using a real database and Medical Director (2.88). All results listed show the average of five tests. As indicated in the following graph, MD2 runs better under Parallels than in Windows natively in each case.
I also did a file repair but the numbers wouldnt fit on the chart; Parallels came in around 400% faster than Windows running natively!
There are a number of things that dont work or run at full speed inside a virtual machine. The most notable of these is graphics ability. An installation of Windows running inside Parallels will only have access to a generic video card driver with 8 MB of memory, so gaming and 3D design are not yet supported. Parallels report that improvements to allow better utilisation of the video power of the Mac are coming soon.
As with all installations of Windows, you need to ensure that anti-virus software is installed within your virtual machine. You also need a licensed copy of Windows to remain legally compliant.
While virtualisation provides the most flexibility, there are several other ways to run Windows on a Mac:
Terminal Services (RDP)
As with Windows and Linux, you can access a Windows Terminal Server from a Mac. This is a great solution for those wishing to use an alternative to Windows on a network of desktops.
BootCamp is an Apple solution that allows you to install Windows natively on your Mac. Unfortunately you need to reboot the computer to access it.
CrossOver & WINE
For the technically adventurous, CrossOver and WINE are solutions that work by allowing Windows programmes to run directly within a Mac or Linux operating system, without needing to install a copy of the Windows operating system!
Parallels Desktop for Mac is the best alternative for a Mac user to run Windows-only applications. There is no downside to this and its highly recommended. VMWare offers a similar experience for Linux users, and some versions of it are free.
In my opinion, a Mac has long been the best choice for the majority of users, beginner through expert. Many have begrudgingly bought a Windows computer instead because their software developer only considers Windows. With the ease and speed of virtualisation there is no longer any reason not to have the elegance and reliability of a Mac computer on your desktop.
Posted in Australian eHealth