AS400 mainframe

Connect with our experts
to get all your answers

    Gain Valuable Answers to All Your AS400 Mainframe Questions

    Created on June 21, 1988, the AS400 system (An integrated system of hardware (AS/400) and an operating system (OS/400) was introduced to the world as a new family of easy-to-use computers.

    Alongside AS-400, you must have come across the term AS400 Mainframe. To clarify any confusion between the two, let’s delve deeper.

    Mistakenly perceived as synonymous, the two terms refer to the same computer system, but the key difference is AS 400 is a mid-range server and the latter is a high-end server.

    Regarding the AS400 Mainframe system, please note that on April 7, 1964, IBM revealed its mainframe computer system known as System/360.

    Interestingly, this family of computers was developed to serve a wide range of scientific and commercial applications, from small to large.

    We hope this has cleared the clouds of confusion between the AS400 and AS/400 Mainframe.

    Moving on, in this exhaustive blog, you will find answers to the top questions that frequently arise in the minds of AS400 users, developers, and decision-makers around the AS 400 mainframe.

    Consult with Experts

    Let’s begin.

    Is AS400 A Mainframe?

    As per IBM, Mainframes are large-range data servers designed to process up to 1 trillion web transactions and simple calculations every day, in real-time, with air-tight security and reliability.

    The mainframe has a unique architecture and design that nurtures high-performance, high-efficiency computing tasks and mission-critical operations where downtime and data integrity are crucial concerns.

    If you are accessing modern business applications, know that you are indirectly interacting with the mainframe computer working behind the curtains to handle crucial functions.

    On the contrary, AS-400 is a mid-range server, not a mainframe (high-end server). Its unique architecture and operating system carve its niche in business applications, database management, and integrated solutions; a diverse set of tasks compared to traditional mainframes.

    What is the Difference Between AS/400 and AS400 Mainframe?

    There’s a persisting confusion about the 2 terms because they belong to the same computer system. But they differ in various ways.

    Let’s see the primary disparities between AS400 vs Mainframe. 

    Size and Power

    A) AS400

    It’s a commodity server undersized than a mainframe, meant to perform special tasks. It comes in small as well as rack-mounted computers.

    It boasts a powerful processor that efficiently runs small and medium-sized business operations.

    B) Mainframe AS400

    It’s a refrigerator-size server that can handle 1 trillion web transactions and simple calculations in a day, without compromising the security.

    Thousands of users can process large chunks of data effortlessly, making them suitable for enterprise-level critical operations.

    User Capacity

    A) AS400

    The server supports limited users as it is meant to handle small-to-medium workloads, however, the users can scale the support up and down as per their needs.

    B) AS/400 Mainframe

    AS400 mainframe computer can easily take up thousands of users and a massive workload while assuring fast and uninterrupted transactions per second.

    Cost Factor

    A) AS-400

    A typical AS400 system can range up to a couple of 10s of thousands of dollars.

    B) AS 400 Mainframe

    A typical mainframe system can go up to hundreds of thousands of dollars.

    Business Utility

    A) AS 400 system

    Typically, the system is used to host business applications, manage databases, business analytics, and more.

    B) AS400 Mainframe System

    The mainframe performs thousands of transactions per second while accessing numerous resources. Mainframe runs critical functions, such as telecommunications or scientific research where dependability is the top priority.

    Let’s understand the difference with the help of this illustration:

    Let’s say there is a retail chain in need of a robust inventory management system to manage the stock levels, purchase and sales data, and supply chain operations across their 1340 warehouses.

    The decision-makers choose to implement the inventory management system on the AS400 platform. Why? Because AS 400’s business applications and database management capabilities offered them the leverage required.

    Furthermore, the platform has enabled a seamless flow of data across the organization, with real-time inventory tracking and reporting and data processing advantages.

    Similarly, they are looking for an all-in-one solution to manage their entire financial transaction process across the 1340 stores.

    The business leaders of the company opt for the AS400 mainframe for its exceptional reliability, high processing power, and high storage capacity, serving many thousand users, while protecting the integrity of the inventory information.

    Connect with Us

    What Does a Mainframe Look Like?

    Traditional mainframes needed a lot of physical space (even dedicated rooms) and were very noisy. However, modern upgrades have led the mainframe computers to fit in almost all environments.

    How Does the AS400 Mainframe System Work?

    One of the popular questions asked is – how does the mainframe system work?

    Let’s demystify its unique engineering:

    Versatile Operating Systems

    The mainframe is designed to run on versatile operating systems such as Linux or Windows alongside special operating systems such as IBM z/OS, and software that reaps the benefits of unique hardware capabilities.

    High Transaction and Data Processing

    The mainframe AS400 excels in supporting a massive number of concurrent transactions and data processing, along with built-in capacity on demand, and built-in shared memory for direct application communication.

    Air-Tight Security

    The mainframe computer offers the best security blanket including built-in cryptographic cards and innovative software. Its users can perform over 1 trillion transactions without breaking a sweat.

    Resilience and Redundancy

    Mainframe resiliency is engineered with multiple layers of redundancy for every feature, from CPUs, cryptography modules, power supplies, cooling, etc. while possessing a stronghold in the ever-evolving landscape of technology.

    Who Still Uses AS400 Mainframe?

    Many companies are still using the mainframe they invested in years ago, and even investing in more.

    It builds a solid foundation for modern businesses such as government organizations, financial institutions, healthcare companies, and many others as emphasized below.

    Get in Touch with our Team

    Finance and Banking

    Over 44 of the leading 50 banks continue using IBM Z mainframe, according to IBM.

    • ATM withdrawals
    • Transaction Processing
    • Regulatory Compliance
    • Online account updates
    • Customer Account Management


    The IBM AS/400 mainframe is used by the top 10 insurers across the globe, according to IBM.

    • Set prices
    • Claims Processing
    • Administer Policies
    • Invest in the right markets
    • Conduct Actuarial and Risk Analysis


    Aircraft manufacturers highly depend on mainframe computers for the timely arrival of planes and people, as per IBM.

    • Ticket reservation systems
    • Handle intricate operations
    • High reliability and continuous service
    • Protection of sensitive passenger data


    23 out of 25 biggest United States retailers continue to use mainframe, says IBM.

    • Highly Efficient Transaction Processing
    • Complex inventory Management
    • Point of Sale (POS) Systems
    • E-commerce Integration
    • Production Planning
    • Quality Control

    What are the Features of the Mainframe?

    The AS400 Mainframe computer boasts a powerful range of features including:

    Multiple Input/Output (I/O) Cards

    The mainframe AS400 is equipped with 160 I/O cards to ensure redundancy and fault tolerance. The card acts as a replacement if another card is malfunctioning.

    Impressive Storage Capacity

    The system has massive storage capacity, allowing users to process large volumes of data, get it interpreted and after processing, receive perfect answers.

    Two Powerful Processors

    One of the special features of the mainframe AS400 is that it has 2 different processors – The primary processor and The System Assistance Processor / SAP. Both the CPUs possess particularly designed cores for enhanced productivity.

    Uninterrupted Functioning

    Typically, users have to pause the system to perform different crucial tasks like updating software on the system which can cause productivity loss.

    In the case of a telecommunications company, it could even cause panic among the customers because of the inability to process. The AS400 mainframe system is developed to function effortlessly all day and all night long for a worry-free experience.

    Advantages of More Than 1 Operating System

    The AS/400 mainframe users enjoy the luxury of hosting various operating systems on a single mainframe. For instance, users can effortlessly host and use z/TPF in coexistence with z/OS.

    Fault-Tolerant Computing

    This is a special feature of the AS400 Mainframe computer which ensures that a large volume of data transported from or to a system doesn’t hurt its ongoing operations.

    Moreover, the system ensures error-free data transfer while moving massive data inside the database. It manages the massive data, processes, and applications, comfortably.

    Clustering Technology

    AS400 mainframe computer supports Parallel Sysplex clustering, a feature that promotes a bunch of up to 32 IBM z/OS systems to be connected as a unified computing system.

    The exceptional function is, that even if 1 system crashes, the work will be continued and completed on the next live system without any performance damage.
    Reach Out to Us

    What are the Benefits of the AS400 Mainframe System?

    Here are the eye-opening strengths that make the AS 400 Mainframe computer a precious asset:

    Reliability, Availability, and Serviceability (RAS)

    The AS400 mainframe system makers lay great emphasis on Reliability, Availability, and Serviceability (RAS), which plays a crucial factor in data processing.

    It’s a boon for modern businesses that demand a rock-solid foundation for effortless operations and critical data processes.


    Data is the oil of the digital economy. From customer information, billing and payment information, social media activities, and whatnot. This critical data needs to be secured, managed, and controlled from the cyber villains while using it efficiently.

    The mainframe AS400‘s security capabilities protect the data while allowing multiple authorized users to harness the data without any hassle.


    Thanks to its robust hardware and software capabilities, as your business grows in partners, customers, and staff, you need not worry about the scalability of the mainframe.

    It’s a reliable technology that evolves with your business needs, while you focus on the business growth. This feature has also enabled many corporations to reap the benefits of reduced total cost of ownership.

    Compatibility Across Generations

    Some applications were written ages ago while some were created yesterday, and the beauty of the AS400 mainframe system boasts the ability to adapt both, ensuring compatibility across generations.

    What are the Challenges Mainframe As400 Faced in the 21st Century?

    Along with benefits, the limitations are an integral part of the AS/400 mainframe.

    Challenges Mainframe As400

    Let’s take the plunge.

    Mainframe Applications are Majestic Elephants That Are Hard to Catch

    Updating and enhancing the extensive legacy mainframe applications pose a serious challenge due to a lack of documentation and expertise.

    Furthermore, the high interdependency of applications makes it prone to downtime and complicated entanglement.

    Limited Automation and Increasing Expense of Testing

    As against the modern development pipelines, limited automation and soaring expense pose a testing challenge in AS 400 mainframe system applications. Additionally, there is no scope for individual component testing because of the complex physical hardware dependence.

    Mainframe Development Requires an Exclusive Stage

    As opposed to the modern software development pipelines that simplify changes with automated testing, the AS400 mainframe computer with its dedicated stage calls for a structured process to mitigate the risk.

    Scarcity of Younger AS400 Mainframe Developers

    Over 60% of mainframe professionals have reached the final chapter of their careers and very few computer science graduates are replacing them.

    While the developers are popularly advancing in modern languages,

    very few curious minds are interested in understanding the depths of COBOL, RPG, and procedural code.

    Mainframe Maintenance Is Very Costly

    The mainframes aren’t cheap.

    Many participant companies reported an average annual spending of $65 million simply on its maintenance, as per the 2022 mainframe modernization business barometer report.

    This doesn’t mean you bid farewell to the decades-long-companion — AS400 mainframe system.

    A proficient and seasoned AS/400 application development partner

    comes at your rescue to modernize your mainframe applications, derive value from your current systems – ensuring a future-proof pathway forward.

    Is AS400 Mainframe Computer Still Relevant in the Modern Business Landscape?

    Despite their decline due to the emergence of modern technologies like the Cloud and low-cost x86 servers, the mainframe continues to make strides in the world of IT infrastructure as emphasized below.

    • The global mainframe market is projected to grow and reach a startling figure of $2.90 billion by 2025, says Allied Market Research
    • 67 of Fortune 100 enterprises continue to use mainframe for their most crucial business functions, as per IBM.
    • Over 74% of respondents believed that the mainframe has a long-term practical use as a strategic medium for their enterprises, as per a Deloitte survey

    With these numbers at your disposal, it’s evident that the ‘big iron’ is here to stay unless the computers start baking cakes.

    Can Cloud Replace the Mainframe AS400?

    The community of naysayers may think the cloud has taken over the mainframe. On the contrary, the cloud is just a polished way of offering the same functionalities that mainframe has been offering for ages.

    It won’t be an exaggeration to say that mainframe computers are the real clouds.

    When you doubt that modern technology will wipe out the existence of mainframe, consider these statistics by IBM:

    • 67/100 Fortune Companies
    • 8/10 Telecom Companies
    • 7/10 Top Retailers
    • 8/10 Top Insurers
    • 4/5 Top Airlines
    • 45/50 Banks

    continue relying on the mainframe.


    Because it is secure, scalable, and dependable — that has set it apart from modern tech for the past many years and will set it apart for the next many.

    What are the Future Trends of AS400 Mainframe Technology?

    Here is a sneak peek into the future of the AS400 mainframe.

    Big Data Analytics

    Mainframes are likely to play a key role in the future of big data. With the growing importance of data, enterprises will require a potent platform such as Mainframe, to process and analyze it faster, with accuracy.

    AI & ML

    Along with Big Data Analytics, the mainframe has joined hands with Artificial Intelligence (AI) and Machine Learning (ML) to train and deploy models.

    AS/400 Mainframe with its integral capability to support the requirements will be an ideal choice, making it a vital part of the future.

    Get the Most of Your Mainframe with Integrative Systems

    As you are armed with the nitty-gritty of the AS400 mainframe, its history, present, and possible future, benefits, and challenges, you are all empowered to make the decision by yourself.

    Still have queries?

    We, at Integrative Systems, are a team of AS/400 professionals with 25+ years of development experience. Reach out to us at [email protected] with your plans, doubts, or ideas for a FREE consultation and we will help you turn them into solutions.

    Related Posts

    Post a Comment

    Leave A Comment

    Connect with our experts
    to get all your answers

      Calculate the savings on your current IT spend by collaborating with Integrative Systems

      Connect with our experts
      to get all your answers

        Fill this form, let your IT story unfold,
        Via the details, our solutions behold.

          Fill this form, let your IT story unfold,
          Via the details, our solutions behold.