Pc or Mainframe

Executive Statement

A mainframe is a very large, powerful, dedicated, multi-tasking computer where enormous amounts of data are processed, sometimes millions of records a day. The mainframe is set up for specific applications and those applications only; which is totally different from a Personal Computer (PC). A mainframe runs a custom operating system specifically written for particular applications while a PC has a generic operating system such as Windows and is built to handle many different programs.

PC’s are multi-tasking but not dedicated with control of the resources usually handled by the computer rather than the user having control over the amount of resources used by any given application. For example, if you were to run 3D Studio Max, it would use 100% of your processor and about 75% of your Random Access Memory (RAM) to render a scene but if you were working with a similar mainframe program you would be able to use the assigned "chunk" of the processing power for rendering and that would still leave the dedicated amount for other applications or users to use (L. Mitzner, personal communication, January 12, 2002).

PC’s and Mainframes Defined

In comparing and contrasting PC’s and Mainframes it is necessary to first understand what a PC and a Mainframe are. Because IBM produced the first personal computer, the term PC came to mean IBM or IBM-compatible personal computers, which excluded other types of personal computers such as Macintoshes, though I rarely hear the term IBM-compatible used anymore when referring to the term PC.

Put quite simply a mainframe is a very large computer that is totally different from a PC. Some of the differences between mainframes and PC's are size, power, ability to dedicate resources, and the amount of data that can be processed. The mainframe is set up for specific applications and those applications only; that is totally different from a PC. For example, you couldn't load Word or Internet Explorer onto a mainframe computer. It is true that, as to processing power, what was a mainframe yesterday is on desktops today, but that is where the similarities end.

The Central Processing Unit (CPU) is the brains of the computer where most of the calculations take place and it is the most important element of a computer system. For the PC the CPU is housed in a chip (known as the microprocessor) such as the Intel Pentium chip. On a Mainframe computer CPUs require one or more printed circuit boards (PC board).

Mainframe is the name that was given to this machine by the industry that came from the way they built the machine by first putting up a metal frame and then installing all of the components or units, such as the processing unit and the communication unit, into this frame hence the term: Mainframe.

PC’s and Mainframes Explained

Personal computers, otherwise known as Microcomputers, are everywhere, on our desks, at home and at work, on tables, in offices, thus making them the most visible form of computers in the world today. Even though they come from many different makers, in different sizes, shapes and colors, the design and technical specifications used for PC’s has remained constant for generations. A personal computer is a stand-alone machine with most of the computing done physically on the computer itself. When networking started to integrate into offices PC'S became connected with network servers, and mainframes.

For applications and large-scale computing purposes of very large corporations, businesses, government, banking and educational institutions, a large company, such as IBM, typically manufactures a mainframe. Historically, a mainframe is associated with centralized computing. Today, IBM refers to larger processors and servers and they emphasize that they can be used to serve distributed users and smaller servers in a computing network.

What do they look like?

A personal computer can be housed in a mini-tower; a mid-tower or a full-tower or it can be the flat desktop housing that has the monitor sitting on top of it. Several years ago, I worked for the IRS and they had a computer room. This room was very large, kept refrigerated and housed several mainframes. These machines were typically 8-9 feet tall, about 3 feet or more wide and they were made of grey colored steel. They had lots of lights and dials and such. The data storage was reel-to-reel tape onto which data was downloaded twice a day.

So how Big is Big?

The main purpose of a mainframe was to run commercial applications and large-scale computing, such as that done by the IRS, and banks where enormous amounts of