PCs vs Mainframes

According to Encyclopedia Britannica, a mainframe computer is a digital computer designed for high-speed data processing with heavy use of input/output units such as large-capacity disks and printers. They have been used for such applications as payroll computations, accounting, business transactions, information retrieval, airline seat reservations, and scientific and engineering computations. Mainframe systems, with remote “dumb” terminals, have been displaced in many applications by client-server architecture.

Encyclopedia Britannica also states that a personal computer is a digital computer designed for use by only one person at a time. A typical personal computer assemblage consists of a central processing unit (CPU), which contains the computer’s arithmetic, logic, and control circuitry on an integrated circuit; two types of computer memory, main memory, such as digital random-access memory (RAM), and auxiliary memory, such as magnetic hard disks and special optical compact discs, or read-only memory (ROM) discs (CD-ROMs and DVD-ROMs); and various input/output devices, including a display screen, keyboard and mouse, modem, and printer.

Mainframe computers are centralized and users access the information on a mainframe via a workstation.  A workstation can resemble a personal computer, but is often a dumb terminal with all the actual computing done on the mainframe itself.   Mainframes are often used to ‘batch’ transactions in financial company, which is one of the best ways to process large transaction volumes and maintain the large databases often required by such companies.


A mainframe is more stable with fewer points of failure or avenues of entry for things like viruses.  Mainframes require less power, cooling, and floor space than server banks.  These factors combine to make a mainframe more reliable than a server bank or PC.  My own PC has crashed three times today.

Some other advantages of mainframes are higher processing speeds and often multiple processors, allowing multiple applications to be used simultaneously and by multiple users.

The disadvantages of mainframes are their large up-front costs, slower running speeds, difficulty in data integration, and of course, finding people skilled in working with mainframes.  When something does go wrong with a mainframe, it rarely can be fixed with a simple reboot.  Even considering that a mainframe will crash less often than a server or PC, it is worth pointing out that while a PC or server crash is an inconvenience, a mainframe crash is potentially devastating.

The first big advantage a PC has is that it is small, even portable in the case of laptops.  PCs are much easier to operate and are inexpensive.  It is fairly easy to integrate data through a PC network, especially if all users are using the same operating system or family of operating systems.  Since the early 1980s, personal computers have been making great strides.  In smaller operations, a PC and server is a much better option than a mainframe, especially when expense is taken into account.

Personal computers are much more versatile than a mainframe, and are easily customized to fit individual needs while still allowing data to be transferred between computers through either a network hub or a central server.   PCs can even be connected to a bank of multiple servers.  Servers however, are best used merely to store data and most applications are run on the PCs themselves.

Nearly any idiot can figure out how to work on a PC with minimal or even no training.  My disabled, elderly, and not particularly bright grandmother could figure out how to get onto her PC and forward copious amounts of junk email to unsuspecting family members, as well as entertain herself with games of solitaire and minesweeper.

PCs cannot be used by many users simultaneously.  Even with a network, it is only data sharing and the data sharing can bog down multiple computers rather rapidly.  A PC is limited to only one processor, and thus some heavy activities, particularly those in the scientific and financial fields, cannot be handled by a PC.  Depending on the application, occasionally only one application can be used at a time.  A PC simply cannot process the amount of data a mainframe can.  PCs are often not as sturdy as mainframes, and have a much shorter lifespan due to both the technology quickly outpacing the current models and the actual quality of parts used in a PC.

Mainframes and PCs both have their uses, and as the technology continually improves, the PC is rapidly overtaking the mainframe.  In many applications, the mainframe has been discarded in favor of the PC/Server model, and it is likely that as time goes by, more and more mainframes will be replaced.  The mainframe does however, have it’s staunch uses and it will take some time yet before the PC/Server model can hope to accomplish the same powerful tasks that a mainframe can do practically in it’s sleep.  In many ways, the mainframe is much like the trains of old. Slowly losing ground to trucks and planes, but for the transportation of many kinds of items, the trains still have no superior.


Mainframe. (2010). In Encyclopedia Britannica. Retrieved February 22, 2010, from Encyclopedia Britannica Online:

Palmer, M., & Walters, M. (). Guide to Operating Systems Enhanced Edition (3rd ed.). Mason, OH: Cengage Learning.

Personal computer. (2010). In Encyclopedia Britannica. Retrieved February 22, 2010, from Encyclopedia Britannica Online:

Thibodeau, P. (2008, February 18). Mainframes fight to keep corporate IT crown. Computerworld, 42(8), 12.

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