Focus On: Can AS/400 and NT Really Coexist?

Over the past ten years IBM’s AS/400 line has found its way into IT departments worldwide. Ninety four percent of the Fortune 100 companies have chosen the reliable, stable, and robust AS/400 as a part of their IT resources. Now, however, NT servers challenge the AS/400 for scaleable business computing. But NT may not be the threat many people think it is. Right now, NT servers are really still just enhanced PCs.

Brief History

The AS/400 has grown up in the past 10 years. Introduced as the successor to System 38, the AS/400 product line has proven to be a winner. Its integration, reliability, simplicity and ease of use has made it the system of choice for mission critical applications such as accounting and databases. In fact, it has been almost too reliable -- the AS/400 is often overlooked when reviewing IT needs because it does not make the headlines the way NT does, even though much of the news about NT is unfavorable. The AS/400 is a wheel that doesn’t squeak, so it is not noticed.

Over the past decade, IBM has continuously improved the AS/400. Several major enhancements have been made; the most notable being the delivery, prior to most other Unix systems, of 64-bit technology in 1995. The AS/400 architecture allows users to run both 32-bit and 64-bit applications on the same machine, while the AS/400e Series is designed to take advantage of the growing interest in e-business by natively incorporating technologies like Java and Domino into OS/400.

Enter NT

Originally developed as a network operating system to link PCs, NT has grown in popularity significantly since its release. Now you will find NT servers in large organizations performing varied tasks. Linked together, NT servers can provide decent computing power and flexibility at a relatively low cost. It is not surprising IT managers consider NT technology attractive, especially in companies with limited IT resources. Choosing NT is easy for many small to mid-sized companies due to the low cost, familiarity with applications, support from Microsoft, and a variety of platforms it supports. Midrange computer systems, like the AS/400, may appear too costly and too much trouble when NT can suffice.

NT servers seem relatively inexpensive (starting under $4,000) when compared to an AS/400 (starting around $10,000). If the need is to place servers in several different or remote locations, the apparent cost savings favors the NT solution. You rarely find a single NT server performing all of a company’s computing functions. Instead, typically several servers work together (an NT farm) with each serving a separate application. For instance, there is commonly a file and print server, a Web server, a database server, a communications server, and a personal productivity server as part of the farm. That means five servers are required to perform the company’s computing needs. While Microsoft may claim that NT can perform all the functions on a single server, the practical application is that you will need several servers to handle the needs of a larger organization.

AS/400 Better Meets the Need

When considering the computing needs for a larger organization, the AS/400 is a better value than the NT solution. A major advantage is the AS/400’s ability to perform several applications at once and still provide reliability. Craig Johnson, IBM’s Senior Competitive Specialist says, "Because you can run multiple applications on an AS/400, you do not need a separate server for each application." In practice, it may require the use of several NT servers to perform the same functions at an equal level of performance as a single AS/400. Ian Jarman, Client Integration Marketing Manager for AS/400 puts it this way, "One of the techniques for delivering client reliability for an application on a PC server is to completely isolate it from all other applications. As people grow they cannot afford to have a single server per application. It becomes very important for the operating system to deliver robustness between applications, and that is what we do on the AS/400."


If the AS/400 is much better than the NT server, why has IBM made it possible for customers to run NT on an AS/400 Integrated PC Server (IPCS)? The answer is actually rather simple -- customers wanted it. Today it is rare to find a truly homogeneous computing environment. Companies have several operating systems and platforms from which they run their business. Jarman says, "In most organizations there is a split between the things they run on NT and the things they run on the AS/400. The IPCS is designed to offer an integrated alternative for those complementary applications that run along side the AS/400."

In cases where NT servers and AS/400 coexist, applications not crucial to the core business generally run on the NT server, while mission critical applications usually run on the AS/400. Applications in areas like personal productivity (for Word and Excel), communications (e-mail and fax serving), print and file serving or Web serving are often delegated to an NT server.

IBM is making it possible for smaller organizations to have easier entry into the AS/400 market. Today, 25 percent of the AS/400 entry level platform (Model 170) are being shipped with integrated servers. This means customers can continue to use the Windows applications they like and move up to a more reliable, robust and stable AS/400 system for critical applications like databases and accounting.

Areas of concern with NT

Unlike the AS/400, NT always seems to be in the headlines, but that does not mean it is time to switch to NT for your enterprise. There are still many problems with NT. Here are just a few:

  • Y2K

NT 3.51 has Y2K problems that Microsoft has not and probably will not fix. Hence you are forced to upgrade to NT 4.0, but Microsoft admits that there may be some isolated problems with NT 4.0 as well.

  • NT 5.0 availability

We still don’t know when a commercial version of NT 5.0 will be ready. At first we were told early 1998, then late 1998; now it is anyone’s guess.

  • Maturity

As much as 85 percent of NT 5.0’s 30 million lines of code are new. How many bugs do you think users will find? If Microsoft is true to form, there will be many problems to fix before it works reliably.

  • Support

Initially, support for NT 5.0 will be limited. Microsoft Certified Engineers (MSCEs) will need to be trained regarding the intricacies and management of NT 5.0, and once trained their market value increases, so retaining MSCE personnel with NT 5.0 knowledge will be more expensive.

  • 64 bit concerns

NT is not 64 bit, and it is not expected to be any time soon; certainly not until way after NT 5.0 is released. When it does become available, there are three issues:

1) Support staff for the 64 bit version of NT 5.0 will be even more difficult to locate and retain.

2) Not only will 64 bit NT 5.0 be new, but so will the 64 bit Merced chip. Dealing with a new operating system on new architecture will be challenging for some and daunting for many.

3) Applications written for 32 bit NT will need to be rewritten and/or recompiled to run on the 64 bit version.

NT as a Competitor

While there may be some direct competition with NT servers at lower levels, Jarman says, "The AS/400 can deliver mainframe type power, at that end of the market NT is not a player." That statement is supported by a recent Gartner Group report showing that NT servers are not on a performance par with the AS/400 (see table).

AS/400 users have a mature, reliable, and proven platform from which to run critical applications. The OS/400 operating system, designed specifically for the AS/400 architecture, takes advantage of the strengths in the AS/400 to run both 32 bit and 64 bit applications, and has several years head start over 64 bit NT. The AS/400’s ability to reliably handle multiple applications has made it the leader in the multi-purpose, multi-application, commercial server market.

Comparing NT servers directly with the AS/400 is like comparing a pickup with a tractor trailer. They both are capable of transporting goods from one point to another, but using a tractor trailer to deliver one pallet of goods would not be cost effective. However, a pickup delivering 40 pallets in 40 trips would be costly and cause undo wear and tear on the pickup. A pickup may cost just 10 percent as much as a tractor trailer, but you would need 40 pickups to match the tractor trailer’s delivery capability. But with both vehicles available, you could use them to make both large and small deliveries. This delivery analogy can be applied to NT servers and the AS/400. Each has its best use in delivering your computing needs. By judicious use of both systems, it is possible for an IT manager to increase the overall productivity of IT resources.


In today’s heterogeneous environments, coexistence is an IT manager’s responsibility. The manager’s goal should be to maximize the benefits and capabilities of the available IT resources. IBM is making that job a little easier by facilitating easier coexistence between NT and the AS/400. This coexistence is not only possible --- it make sense on several levels:

  1. End users continue to use familiar Windows applications -- no retraining.
  2. By moving non-production related applications like web serving, e-mail, and graphics applications to NT servers, computing power for critical applications is enhanced.
  3. Critical applications can be simultaneously run on a reliable, stable AS/400 platform while complementary applications are run on an NT server.
  4. The AS/400 provides a more powerful computing tool in a smaller footprint than an NT server farm.
  5. Coexistence makes the best use of all IT resources.