Moore's Law has been predicting the exponential growth of computing power for over 50 years.

Since the invention of integrated circuits in the 1950s until today, Moore's Law has pushed technological development through many challenges. While exponential growth has largely continued, integrated circuits are rapidly approaching the processing power of the human brain.

We'll discuss the state of things today and whether Moore's Law still applies.

What Is Moore's Law?

In 1965, Gordon E. Moore (1929-2023), co-founder of Intel, reported that the number of transistors per square inch on an integrated circuit had doubled approximately every year since its invention in 1958. At the time, Moore predicted this trend would continue for at least ten more years.

In his 1965 paper, Cramming More Components Onto Integrated Circuits, Moore wrote:

With unit cost falling as the number of components per circuit rises, by 1975 economics may dictate squeezing as many as 65,000 components on a single silicon chip.

This projection wasn't quite right. By 1975, chips only held 10,000 transistors each, so Moore updated his prediction to a doubling approximately every two years and later to every 18 months. Moore's (updated) Law held true for almost 50 years.

Moore's Law Graph
Image Credits: Max Roser, Hannah Ritchie / Our World in Data

Around the 2010s, growth of transistor density started slowing down. Today, over 50 billion transistors find space on a single chip, and we've seen a doubling approximately every two and a half years.

Strictly speaking, Moore's Law doesn't apply anymore. But while its exponential growth has decelerated, we'll continue to see an increase in transistor density for a few more years. What's more, innovation will continue beyond shrinking physical components.

Why Did Moore's Law Persist?

When Moore's Law became widely accepted, the industry began establishing road maps and setting goals based on Moore's projection. As the production of integrated circuits became more complex and involved the interplay of various specialized companies, a plan was needed to help all parties set individual targets and advance at an equal pace.

From 1998 until 2017, the International Technology Roadmap for Semiconductors (ITRs)—a yearly report produced by a group of semiconductor industry experts—provided the basis for such a plan. The ITRS documented the research in all areas relevant to semiconductors and provided timelines for up to 15 years into the future. Today, the International Roadmap for Devices and Systems (IRDS) has taken on this task.

Ultimately, Moore's Law has been serving as a vision for an entire industry and has become something like a perpetual self-fulfilling prophecy. But it's bound to hit another major roadblock in the mid-2020s.

More Moore Meets More Than Moore

As nanoscale transistor density is hitting molecular limits, it's becoming impossible to cool circuits. Consequently, Moore's Law will taper off, which Moore himself predicted would happen after around 2020. This, however, may not spell the end of Moore's Law. Rather, we'll see Moore's Law enter into a new dimension.

In a 2010 White Paper, ITRS's Arden et al. postulated:

The industry is now faced with the increasing importance of a new trend, “More than Moore” (MtM), where added value to devices is provided by incorporating functionalities that do not necessarily scale according to “Moore's Law.“

More Moore

Moore's Law (aka "More Moore") has been pushing technology to shrinking the size of physical components while simultaneously improving density and performance. The proposed "More than Moore" (MtM) methodology will continue to fuel the ITRS's roadmapping efforts.

Meanwhile, Intel itself has developed new technology, such as 3D CPU transistors or GAAFET, which is poised to 10x processing performance and efficiency. These advances alone could lead to new CPUs that will uphold Moore's Law well beyond 2025.

More Than Moore

More Than Moore
Image Credits: Arden et al. / "More-than-Moore" White Paper

More than Moore (MtM) relies on alternative technologies, such as system in package, solid-state lighting, integrated radio frequency functions, or organic technology. It complements More Moore and may extend the validity of a renewed Moore's Law for another decade and beyond.

Fun Fact: Due to its continued success, Moore himself once described his law as a violation of Murphy's Law: "Everything gets better and better."

The Flip Side of Moore's Law

On the one hand, Moore's Law has fueled technological advancement. An entire industry was driven to keep up with Moore's projection. As a result, many of Moore's other predictions about technology, e.g. home computers or personal portable communications equipment, all driven by tiny CPUs, have also come true.

Today, all of us enjoy and benefit from this technology, we have become used to fast-paced developments, and are anticipating future innovations. So you, a representative of the customer side, are said to keep expecting and demanding technological advancements. Do you?

On one of the flip-sides of Moore's Law, however, we have The Great Moore's Law Compensator (TGMLC), also known as software bloat or Wirth's Law, and several derivatives. TGMLC is based on the adage coined by Swiss computer scientist Niklaus Wirth, who in 1995 quoted Martin Reiser in his paper A Plea for Lean Software:

Software is getting slower more rapidly than hardware becomes faster.

So in essence, end users don't necessarily benefit from developments on the hardware side, as software developers feel compelled or liberated to create products that are equally more complex and resource hungry.

A popular example is Microsoft Office. In 2008, Randall C. Kennedy, a former Intel employee, demonstrated TGMLC using a standard computer of the year 2000 running Office 2000 and a standard computer of the year 2007 running Office 2007. When both versions of Office ran the same task, Office 2007 did so at half the speed of Office 2000.

So, you're not crazy when your new computer seems slower than your old one after very little time. Chances are, you merely updated your software.

Moore's Law Remains Relevant

More importantly than predicting the future, Moore's Law has been a guiding principle, driving integrated circuit development for more than half a century. Despite repeatedly facing seemingly unsurmountable challenges, an entire industry kept collaborating to produce ever-new innovations. As such, Moore's Law proves that goals can shape our future.

Moore's Law will continue to drive innovation, but possibly in ways we can't yet fathom today. Currently, the IRDS considers new semiconductor materials, artificial intelligence, and price developments of rare earth metals its main drivers of future innovations.