Connectix is known for making both powerful allies and powerful enemies for its innovative , but often controversial, achievements in the field virtual machine software. The company entered a protracted intellectual property dispute with Sony after it developed software that emulates Sony PlayStation hardware on PCs. On the other hand it's enjoyed support from Microsoft for making it possible to run Windows virtual machines on the Macintosh platform, just as VMware does for Linux users.

Connectix most recent software recent release, Virtual PC for Windows, mirrors the company's achievements on the Macintosh platform in the x86 hardware environment. Put simply, it makes it possible to run Windows, Linux and a range of other x86-based operating systems as guests of a Windows based host.

Virtual PC is the kind of software application that gives some network engineers and software developers proof that the almighty loves IT professionals. It provides a safe platform to install and test multiple operating systems in isolation without disturbing the host operating system. Ultimately, any organisation that would ordinarily need to duplicate hardware in order to meet diverse software demands can benefit from Virtual PC.

It allows network engineers to explore hardware, software and network, compatibility and interoperability issues without expending time and energy setting up sophisticated arrays of equipment. Larger enterprises and organisations can upgrade their SOEs (Standard Operating Environments) without being tethered to older operating systems by legacy applications. Software developers can carry out quality testing in a broad range of system environments and support centres can address a diverse range of customer needs (operating systems) with the flexibility to use lower cost methods.

There are technical limits guiding Connectix recommendations for host operating system choice - the company suggests Windows NT 4.0, 2000, ME and with less confidence, 98. However, Virtual PC for Windows supports a much larger range of operating systems, as guests: DOS 6.22, Windows 3.1, Windows 95, Windows 98, Windows NT, Windows 2000, Windows ME, OS/2, NetWare and number of distributions of Linux and BSD.

The number of systems you choose to install is only limited by the amount hard disk space you have available, but the number you can run simultaneously is restricted by available RAM. It's a simple matter of arithmetic; add RAM according to the requirements of each OS you wish to run concurrently.

Partitoning vs. Virtual machine solutions

Disk partitioning is the only serious competitor solution to machine emulation software but it is inferior in many respects. Anyone familiar with the use of disk-partitioning methods in the creation of multiple-OS machines will be able to calculate the amount of pain that virtual machine software can circumvent. Disk partitioning has become easier since PowerQuest developed a civilised GUI for its disk partitioning application, PartitionMagic, but the process of creating, formatting and organising partitions is still a slow process. And, for the amount of data-risk it carries, medically it could be compared to major surgery.

There are secondary advantages associated with using Virtual PC. Dual-boot systems don't offer the ability to run operating systems concurrently and require the user to re-boot each time he or she wishes to access a supplemental operating system. Switching between operating systems under Virtual PC is as easy as switching applications.

Virtual PC offers more freedom to experiment and take risks with supplemental operating systems; if a partitioned operating system is destroyed it takes a long time to re-create it. Virtual PC corals each separate operating system in a single file making them easy to discard or replace - the software includes a feature that gives the user the option to save or changes to each guest OS after closing each session.

Virtual PC lets you use disk space more efficiently. It lets you drag and drop files between the host and guest operating systems so there's no need to waste disk space, setting it in a partition of fixed size. You need only set aside as much as is necessary for the guest operating system source file and store data files as and where you think fit. If you do wish to have operating systems within separate partitions they can be incorporated into Virtual PC's boot manager.

Networking

In order to provide an authentic virtual environment for heuristic applications and a natural user-experience, machine emulators need to be able to integrate with network environments as invisibly as they do with system hardware.

Virtual PC's default network mode, Shared Networking, relies on an in-built network address translation system that lets each guest operating system assume the address of the host seamlessly. An alternative mode, Virtual Switch, is available if the machine needs to run network service or be visible to the outside network for any other reason. Unfortunately, Virtual Switch is only available if Windows 2000 is the host operating system and regardless of which mode you use, all guest operating systems must share the same network card (the host can occupy a separate network card).

If you're cautious about permitting an untested operating system on to your SOE or you're developing complex Web-based enterprise applications, Virtual PC allows you to test the network inter-operability of guest operating systems with the host on a virtual network, isolated inside the PC. The virtual network supports of common networking protocols such as TCP/IP, NetBIOS, IPX/SPX and IBM SNA.

Performance

In order to simulate machine hardware Virtual PC vacillates between exploiting the host's device drivers to simulate hardware and competing with the host operating system to gain control over CPU and RAM. Connectix says the virtual machine retains around 80 to 90 percent of CPU performance but disk intensive tasks degrade performance by up to 40 percent. Alas, no good news for gamers; the virtual machine is incapable of emulating audio and complex video tasks performed by modern gaming hardware.

Virtual machine performance is highly dependent on available RAM and this the main disadvantaged associated using this class of emulation products as opposed to partitioning solutions, to run multiple operating system. Connectix says that Virtual PC will run two operating systems with varying degrees of success with a minimum of 128M of RAM, but recommends using 256M. In this case the recommendation is not one that can be ignored. Anything less wouldn't be feasible.

The cost of the RAM must be considered with cost of owning and using the product. A single-user license for Virtual PC for Windows is AU$579 (at the time of writing FirmwareDesign has not finalised pricing for volume purchases). Depending on how much additional RAM you need to purchase the total cost of owning the product could be 1000 percent higher than owning disk-partitioning software such as PartitionMagic.

Virtual PC for Windows is unlikely to interest amateurs and tinkerers. It is most likely to benefit professionals who stand to benefit from offsetting the purchase price of the software against savings on hardware purchases.

Connectix Virtual PC for Windows
Company: Connectix
Price: AU$579 per single-user license
Distributor: FirwareDesign
Phone: 1300 369 951

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