computer sizes

Computers are found everywhere nowadays and there are many different ways people are using them. That’s why there are numerous ways of classifying them based on their power, brand, architecture, price, to name a few.

Today, we are going to talk about a specific classification of computers that most users may not even be aware of. We are talking about classifying computers based on their size. By this we don’t just mean the size difference between laptops and desktops, even though this particular example does fall into this classification as well.

Classification of computers based on their size does not only refer to their dimensions, if not to their applications and power capacity. Roughly speaking, there are four different types of computers based on their size which are the ones we will be mentioning below:


The term “microcomputer” is also known now a days with the term “personal computer”, but they were named microcomputers when they were introduced to the masses, thanks to the emergence of microprocessors. One of the most well-known early microcomputers was the Altair 8800, which was released way back in 1975.

Today, the moniker is used as an umbrella term for desktop machines, laptops, ultra-books, onboard computers found in cars or planes, gaming consoles, including those that are hand held, as well as portable devices, such as smartphones and tablets. Palmtop computers and PDA devices, which are now obsolete, are also considered microcomputers.

Microcomputers make up the majority of computers in the world, and are the first thing we think about when someone mentions the word “computer”, which is part of the reason why the majority is unaware of minicomputers, mainframes, and supercomputers, despite relying on services provided by them every day.


Minicomputers fit right in between the most powerful microcomputer, and the least powerful mainframe. This type of computer is also called a mid-range computer on occasions. However, today, the term is largely archaic, because true minicomputers have been relegated to the pages of history.

Nowadays, small to midrange servers are used for business and scientific applications, which require computers that are able to serve multiple users at the same time. Minicomputers were first introduced in the 60s by IBM.

In terms of computing power, minicomputers are capable of multitasking and multiprocessing, and are more powerful than desktop computers, and less powerful than both mainframes and supercomputers. Some of the minicomputers used today are SPARC, POWER, and Itanium-based machines developed by Oracle, IBM, and HP.

Minicomputers started disappearing from the market thanks to microcomputers becoming more powerful and cheaper, and because of the development of local area network technology which, in essence, enable several much cheaper microcomputer to function as one large and expensive minicomputer. One of the largest computer manufacturers which disappeared from the market at that time was DEC (Digital Equipment Corporation), which was second only to IBM.

Mainframe Computers

Mainframe computers, or simply mainframes, are larger and more powerful than minicomputers. In fact, their computing power, massive storage space, and the ability to work reliably without ever breaking down is what makes them one of the cornerstones of modern business operations, which requires the ability to process large amounts of data.

Another characteristic of mainframes is that they are not only able to multitask and serve multiple users, but also capable of running multiple operating systems, and switching between them with end users not even noticing. To put their processing power into perspective, imagine up to several hundred servers and their ability to process information. That’s how powerful mainframes are.

The origin of mainframe computers dates all the way back to the 1940s. Throughout the entire history of mainframes, the most popular manufacturers have always been IBM, Hitachi, and Amdahl. As we have pointed out previously, mainframes are the foundation of businesses which depend on reliable, large-scale computing operations.

For instance, all major IT giants, as well as all of the biggest companies in the world rely on the power of mainframe computers. Their application also extends to the fields of medicine, e-commerce, banking, insurance, security, government operations, as well as making sure that certain items, such as utilities, function smoothly on a large scale.

Although minicomputers haven’t been able to fight the emergence of cheaper and more powerful technology, mainframes are much more impervious to that, simply because of their sheep power, stability, and compatibility with all platforms. In fact, they are not only able to run the most complex and demanding applications which currently exist, but also those which were written several years, or even decades ago.


These are by far the most powerful type of computers currently in use today. As opposed to mainframes, whose performance is measured in MIPS (million instructions per second), computing power of supercomputers is measured in FLOPS (floating-point operations per second). The largest supercomputers in the world are capable of performing several quadrillions of FLOPS.

Supercomputers were introduced in the 1960s, with the name Cray being associated with the majority of supercomputers released at that time. In the 1970s, the power of supercomputers was modest by today’s standards, as they only featured a handful of processors.

A huge leap in their performance happened during the 1990s, as supercomputers featuring thousands of processors began to emerge. Today, supercomputers which have tens of thousands “stock” microprocessors are considered standard. The most powerful supercomputer in the world is Tianhe-2, built by China, and is capable of performing up to 33.86 quadrillions of FLOPS.

Supercomputers are mostly used to perform extremely complex and computing-intense operations, such as weather forecasting, all kinds of simulations and modeling, climate research, space and Earth exploration, analyzing the structure of large molecules, fluid dynamics, nuclear bomb detonation simulations, and cryptanalysis.


Although computing power is something that is relative and keeps on changing over the course of time, with microcomputers of today being equally powerful as supercomputers of tomorrow, classifying computers based on their size is also done by their application as well. While minicomputers are mostly a thing of the past, the remaining three types of computers are still going strong today.