The Power Mainframe

Mainframes are high-performance computers used by large enterprises for large-scale computing applications with high demands for reliability and security, such as bulk data processing, process control, industry and consumer statistics, enterprise resource planning (ERP), and financial transaction processing. Often called “Big Iron”, distinguishing itself from minicomputers—now generally called servers—and smaller departmental systems. Historically, mainframes have been associated with centralized computing, where processing is performed on the mainframe and displayed in input from a terminal. Today that distinction is blurring as mainframes continue to evolve and servers becoming more powerful.

While rumours and reports have suggested the impending obsoleting of mainframe computing, mainframes remain critically important in nearly every industry. Even with the success of distributed computing, today the bulk of corporate and government data still resides on a mainframe.

Evolution

Since its introduction in the late-’50s the mainframe continues to evolve, seeing improvements in:

* Processor speeds, physical memory and memory addressing capability

* Their ability to dynamic upgrade hardware and software

* The automation of hardware error checking and recovery

* The handling of devices for input/output (I/O) and the paths(channels) between them and processors, as well as more sophisticated I/O attachments

* Their ability to divide their computing resources into multiple, logically independent and isolated systems running its own operating system (OS)

* Clustering technologies and the ability to share data

In many cases, the term mainframe has moved from a description of once room-sized computers to a style of computing that continues to be used in large-scale enterprisesBecause of their reputation for reliability, mainframes often host the most important, mission-critical applications

Mainframes today

Unlike PCs, the mainframe’s work is typically done all behind the scenes and seamless to users. In fact, early mainframes operated in batch mode solely for back office applications

Today the mainframe is used for:

* Large-scale transaction processing

* Concurrent support for thousands of users and applications

* Managing terabytes of data in databases

* Handling large-bandwidth communications

Today they are distinguished by their reliability and high resistance to malware threats—like email viruses and Trojans—typical to PCsThe ability to partition a large system into multiple smaller systems, called logical partitions or LPARs has also become a common requirement of mainframe systems. These LPARs add flexibility, reliability and performance to mainframes.

Mainframes have the unique ability to make available a pool of processors that can configured for specific work In addition these pools of processors, mainframes have a network of special microprocessors called controllers—invisible to the OS or application programs—that control the system as a whole.