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What Is Mainframe?
A mainframe computer, also called “big iron,” is a high-performance business computing system known for its large size, extensive storage and memory capacity, processing power, and high level of reliability. It is designed for large-scale data processing and critical enterprise applications. A single mainframe can replace dozens or even hundreds of smaller servers.
Early mainframes are explained as large, room-sized metal frames first introduced in the 1950s. Some people think of them as obsolete technology. However, modern mainframe technologies support cloud computing, big data analytics, and artificial intelligence (AI). They can even support agile development methodologies (albeit with some configuration) to improve development speed and collaboration.
The definition of the mainframe has really changed with the times. IBM, a company name that is synonymous with mainframe computers, describes today’s mainframe as a style of computing – including applications, operations, and operating systems (OSs).
Common characteristics of mainframes include:
- Nearly all have the ability to run mainframe operating systems (e.g., z/OS, z/VM, Linux for System z).
- Mainframe systems can add or hot-swap system capacity without disruption.
- Are designed to handle very high volume input and output (I/O) and emphasize throughput computing.
- Provide strict backward compatibility with older software.
What are mainframes used for? They are primarily used by large organizations for mission-critical applications requiring high volumes of data processing. Industries using mainframes include banking, finance, health care, insurance, public utilities, government, and a host of other public and private enterprises.
Key Takeaways
- Mainframe computers are generally known for their large amounts of storage, memory, processing power, and high level of reliability.
- They are used for mission-critical applications requiring high volumes of data processing.
- Mainframes play a central role in the daily operations of many of the world’s largest Fortune 1000 companies.
- Mainframes excel at reliable volume computing in domains requiring integer operations (e.g., financial, indexing, comparisons).
- A single mainframe can replace dozens or even hundreds of smaller servers.
History of Mainframes
Modern mainframe history began in the 1950s with IBM’s commercial introduction of the IBM 701. Other notable early vendors of the 1960s and 1970s include Hitachi and Amdahl. Since its inception, mainframe computers have dominated the landscape of large-scale business computing.
Mainframe computers play a central role in the daily operations of many Fortune 1000 companies. While modern forms of computing, such as cloud and hybrid cloud, are widely adopted, the mainframe occupies a coveted place in today’s e-business environment for handling mission-critical applications and high-volume data processing.
How Mainframe Works
Mainframe computers are designed to handle and process large-scale data while simultaneously running critical applications. They essentially work like a central hub – managing data from multiple users or systems. Mainframe servers effectively support thousands of users or applications concurrently while ensuring data integrity and security.
This is possible because of:
- Advanced processors optimized for high-speed multitasking
- Large memory capacities to store and process vast datasets
- Specialized operating systems designed for stability and scalability
Keep in mind that mainframes are primarily used by IT professionals. While modern mainframes may provide more accessible interfaces, like graphical user interfaces (GUIs) and web-based applications, they are not user-friendly for casual users.
Mainframe Features
- High reliability
- Multiple operating systems
- Processing power
- RAS – reliability, availability, and serviceability
- Scalability
- Security
- Storage
- Transaction processing
- Virtualization
Difference Between Mainframes and Supercomputers
The main difference between mainframes and supercomputers is their typical application: mainframes excel in reliable volume computing (e.g., financial tasks), while supercomputers, a type of high-performance computing (HPC), specialize in floating-point operations for modeling phenomena like weather.
Despite the continual change in IT, mainframe computing remains stable, secure, and compatible. For those who think there is no use for the ‘big iron’ in modern computing, they would be surprised. Who uses mainframes? The truth is that we are all mainframe users in one way or another.
Mainframe vs. Server
The primary difference between a mainframe and a server is purpose and scale.
| Mainframe | Server |
|---|---|
| Designed to handle large-scale data and applications | Supports smaller-scale tasks and applications |
| Handles thousands of users concurrently | Handles fewer users simultaneously |
| Optimized for high-speed multitasking | Optimized for general-purpose computing |
| Uses specialized operating systems | Uses common operating systems |
| Suitable for critical enterprise-level tasks | Suitable for small to medium businesses |
| Not user-friendly for casual or end-users | Offer more accessible and user-friendly interfaces |
Mainframe Examples
A high-performance business system designed for large-scale computing is a general mainframe definition, and examples include:
- 1951 – UNIVAC I
- 1964 – IBM System/360
- 1970 – Amdahl 470 V/6
- 2000 – Hitachi AP10000
- 2020 – Fujitsu GS21 3600
- 2022 – IBM z16
Mainframe Computers and Security
Mainframe computers are generally considered secure. However, they are used in industries like healthcare, banking, and government – making them targets for more sophisticated cyberattacks (i.e., exploits via phishing, malware, ransomware, and credential stuffing attacks).
Mainframes have security built into their architecture and operating systems. Rather than relying on tools like server antivirus software and frequent updates, they use integrated hardware and software-based security measures.
Examples of mainframe computer security features include:
- Built-in intrusion detection and prevention tools
- End-to-end data integrity checks
- Enterprise-grade encryption
- Network isolation and segmentation
- Role-based access control (RBAC) systems
- System redundancy and failover mechanisms
- Tamper-resistant technology
Mainframe Pros & Cons
Pros
- Built-in security features
- Handles large-scale data and applications
- High reliability and uptime
- Manages thousands of users concurrently
- Supports legacy applications/systems
Cons
- Complex maintenance requirements
- High cost and potential vendor lock-in
- Not user-friendly for casual or end-users
- Requires specialized knowledge/skills to operate
- Potential target for sophisticated cyberattacks
The Bottom Line
The mainframe definition refers to a high-performance business computing system designed for large-scale data processing and critical enterprise applications. Known for their reliability, scalability, and ability to handle thousands of users concurrently, mainframes remain essential for industries like banking, healthcare, and government.
While many think of a mainframe as an outdated system from the 1950s, keep in mind that mainframe computers have changed with the times. Today’s mainframes support technologies like AI, cloud computing, and big data analytics. While complex and costly, they offer built-in security and high reliability, ensuring continued relevance in modern computing.
