Moore's Law reaches crunch point as transistors stop shrinking
It is a maxim that has held true for decades, powering the rise of personal computers and the democratisation of technology. As the silicon transistors that make up computer circuits shrink, engineers are able to fit exponentially more onto every microchip, making computers cheaper and more powerful. But Moore’s Law – a rule that has seen computing power roughly double every two years for the last five decades – is being challenged as those transistors reach their minimum possible size.

According to the latest International Technology Roadmap for Semiconductors (ITRS), a joint report from chip giants including Intel and Samsung, by 2021 transistors will shrink to a point at which it is no longer economically viable to make them smaller.

Transistors are the fundamental building blocks of computers, switching between the binary “on” and “off” that makes up the language of computers.

Since Intel founder Gordon Moore proposed that the number of transistors on an integrated circuit would double every two years in 1965, the law has held remarkably steady, leading to enormous advances in computing and making technology dramatically cheaper.

While a couple of thousand transistors might have fit on a microprocessor in the early 1970s, now more than a trillion do, and today’s cheapest mobile phones easily outstrip what were once considered supercomputers.

The ITRS said transistors will reach their economic minimum in 2021, meaning that while they could theoretically be made smaller, the costs of doing so are prohibitive. However, it said that this would not be the end for Moore’s Law, as manufacturers find increasingly innovative ways to squeeze more switches into a given space.

To maintain the rapid advances of recent years, the report said that chip companies will now focus on stacking sets of transistors on top of each other to create so-called “3D” processors, although this runs the risk of them overheating.

The increased costs of whittling down transistor sizes to their economically viable limit has led to a wave of consolidation in the semiconductor industry, meaning there are now just four main manufacturers: Intel, Samsung, the Taiwan Semiconductor Manufacturing Company and the US group GlobalFoundries.

With Moore's Law in doubt, many companies are exploring quantum computing - which takes advantage of states in between the binary "on" and "off" to greatly increase processing power.


What is quantum computing?

Quantum computing is based on quantum bits or qubits. Unlike traditional computers, in which bits must have a value of either zero or one, a qubit can represent a zero, a one, or both values simultaneously.

Representing information in qubits allows the information to be processed in ways that have no equivalent in classical computing, taking advantage of phenomena such as quantum tunneling and quantum entanglement.

As such, quantum computers may theoretically be able to solve certain problems in a few days that would take millions of years on a classical computer. (Source: Nasa)