IBM i vs AS400: How Are They Different?

What is the difference between IBM i vs AS400? There is a lengthy history of the AS400, now known as the IBM Power Series, which uses the IBM i operating system. With a long history comes some jargon and concepts that might become “sticky.”

Application programming interfaces (APIs) or integrated web services are becoming the digital representation of an organization in today’s interconnected world. Now, businesses use integrated web APIs or IBM i web services that help enterprises to enrich, modernize, extend, and reuse their core business assets well beyond their original scope of design.

In this article, we will explore the difference between IBM i vs. AS400. Moreover, we will talk about the journey and concepts of IBM i/As400 systems in detail.

What Is The AS400, IBM i, Or IBM i Series?

IBM introduced AS400 (Application System/400) at the beginning of 1988. AS/400 is a powerful desktop that was specially designed for small and mid-sized businesses. These midrange lines of computers have been popular in many organizations since the 80’s due to their performance, reliability, scalability, security, robustness, and low-cost features.

IBM i/As400 systems have their own OS/400 operating system and embedded database. In 2000, AS400 was rebranded or modified to IBM i Series server. Later in 2006, the iSeries was replaced with the IBM system i. IBM i is the current operating system that supports all IBM Power systems.

What Is The AS400 Or iSeries Called Now?

Over the years, the software and hardware of IBM AS400 midrange servers have undergone several names changing updates and revisions. The name change revisions have included AS400, Series Servers, and IBM system i.

All products of the IBM system i and p series were rebranded again and launched the current version of IBM AS400 or i Series systems known now IBM power systems. The current IBM power systems run on an updated IBM i operating system.

What Should You Know About IBM i “AS400 / iSeries” Systems?

The IBM AS400 mid-range computer replaced the System/38. They support System/36 in a runtime environment. Although it is simple to use for end users, the internal architecture of IBM i / AS400 is complicated that is integrated with the database, security, hardware, and software.

The IBM Power System, formerly known as the AS400, is highly advanced, unique, quickly adaptable, and capable of incorporating innovations. The Machine Interface (MI) keeps separate the software and hardware components of IBM i so that improvements to one do not affect the other.

In other words, the AS400 has separate hardware and software sections.  The AS400/IBM Power System’s OS already has a built-in database, therefore the user doesn’t need to perform any further installations. To explore more details about AS400 system visit this link: what is as400?

What Is IBM i Operating System?

IBM i operating system runs on the latest power series systems. It is specifically designed for the IBM i platform. Primarily, IBM i built to adapt to changing business and computing requirements. They help in managing different services, software, and hardware resources. The main characteristic is ‘integration’, represented by ‘i’ in IBM i. So, we can integrate more advanced features with fewer resources. Explore what IBM i is.

IBM i vs. AS/400: Why Can’t They Be Compared?

It is hard to compare IBM i vs. AS400 clearly in words. There is still a misunderstanding over whether AS400 and IBMi are the same because of multiple name changes. Additionally, this confusion between AS400 software and IBM i has created a big growth barrier to digital transformation for businesses in the market that are adopting IBM technology.

Comparing IBM i vs. AS/400 is similar to comparing two different flavors. If we compare both of them technically, they would be compared between hardware and software. AS400 software is a physical server created by IBM in the 1980s. Whereas IBM i is the OS for AS400 or IBM Power systems today.

IBM i vs. AS/400: Getting Clear On The Difference?

IBM i, which runs on IBM Power systems has a long successful history and is popular for excellent support, reliability, and scalability.

IBM i vs. AS/400? when we compare both, we realize that IBM i and AS400 (iSeries) are not the same. Here, I found a clear difference between both. IBM i is an operating system running on the modern IBM Power systems. Whereas AS400 and iSeries are old or legacy hardware servers. AS400 is the ancestor of the IBM i platform.

However, this wonderful technology is still referred to by its users as “AS400” or “iSeries” in an innocent manner.

Has IBM i Now Had More Life Than The AS/400 Did?

IBM i /AS400 iSeries is currently more reliable than AS/400 Did. Now, IBM i and IBM Power System’s new technologies replace the as400 computer system as the most well-known brands in the business.

  • IBM i has recognized the value of open source. Therefore, the IBM i platform allows businesses to integrate Open Source Solutions and modern RPM software management methods in their applications.
  • IBM i is highly secured as compared to AS400 software.
  • The security of IBM i is growing consistently. In the IBM i architecture, the old protocols have been replaced with new access controls.
  • IBM i is more modernized. We can modernize the legacy IBM green screens with a modern user interface. So, these IBM i applications can operate in web browsers and mobile devices. We can modernize the entire infrastructure in IBM i without losing any data.

Is The AS/400 Dead?

The AS400 system was introduced in the ’80s. That’s why most people assume that the AS400 is considered dead now, but we do not agree with this assumption. The IBM i series, AS400 mid-range lines of systems, has undergone multiple rebranding updates and revisions.

Despite all these, the IBM AS400 platform is still an important element of many of the world’s top organizations. IBM i series AS400 hardware and software provide high security and other advanced features such as scalability, reliability, robustness, and enable quick processing of large amounts of data. Currently, companies widely use it for working with resource-intensive applications such as ERP, banking, or mission-critical systems.

Why Is AS400 i Series (AS/400, IBM i) Still In Demand In 2022?

The IBM i series AS400 systems are constantly improving day by day and provide the functionality for businesses that today’s business requires. Organizations now widely use the IBM i platform, continuously improving their productivity. AS400 iSeries platforms are still in demand due to the following features:


Businesses can quickly start with a 4-core server at a low cost. Further, we can upgrade the 256 core machines with changing business requirements. So, the As 400 iSeries platform is best for all company sizes.


The IBM i/As 400 platform offers high security for your programs and data.

High Performance With Reliability

The system has enterprise-class reliability, and tools that are widely accessible for approximately 100% uptime.

Logical Partitioning (LPAR)

We can run multiple operating systems consecutively on a single IBM i device using this feature. It allows us to create separate partitions for each operating system. Moreover, it ensures that no one OS uses the space or resources of another.

Software Integration And IBM i Application Modernization

AS400/ IBM i platform supports all existing programs. In addition, we can integrate native and open-source development languages (SQL, Java, .NET, PHP, and C++) in the legacy applications for application modernization.

IBM i operating systems provides a menu-driven interface, built-in database (DBMS, DB2/400), multi-user and IBM 5250 green screen terminal support, security, printers, and communications. The IBM i /As400platform continues evolving every day and incorporating modern technologies in their IBM i applications that are most popular today such as machine learning, data analytics, and Artificial intelligence with powerful CPUs and technology enhancement.

How To Modernize AS400 iSeries (AS/400, IBM i) With LANSA?

LANSA is a powerful IBM i modernization platform that offers several solutions for modernizing the AS400/IBM i or iSeries upgrades. LANSA offers different tools that help in IBM i legacy application modernization and building new solutions.

One of the most popular tools of LANSA for IBM i green screen app modernization is aXes. We can instantly transform the AS400/IBM I 5250 green screens into a modern web and mobile interface without modifying the source code. So, we can add more features to legacy IBM i applications based on the business requirements.

Visit LANSA today to modernize your AS400 iSeries (AS/400, IBM i) with us!

LANSA Editors: