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Welcome to The Drive, a weekly column looking at some wacky, interesting, cool, and pivotal things within the tech space! Curated by PC Hardware Lead Editor Richard Edmonds through almost two decades covering the sector.

The microprocessor is a computer processor of arithmetic, logic, and control circuitry on a single integrated circuit. The easiest way to think of a microprocessor is to take a desktop-class processor from companies such as AMD or Intel. They're large enough for physical analysis and are used in most electronic devices, including the one you're reading this article. Before the microprocessor, computers used bulky circuit boards but now these CPUs are small enough to fit inside a smartwatch. Without them, the world wouldn't be anywhere near as technologically advanced.

Powering the advancements of today

Inside almost everything we rely on

The microprocessor takes an input and runs some operations, producing an output. A microprocessor isn't the same as a system-on-a-chip (SoC) though it is often used interchangeably with the term central processing unit (CPU). Although small, these capable devices have millions of small components. At a high level, a microprocessor takes data from system memory, decodes the instructions, executes the operation, and moves the result to memory.

Processors can have multiple cores (and threads), allowing the device to handle multiple instructions per clock. Earlier microprocessors had a single lane for handling data, but the latest AMD and Intel chips have multiple lanes and faster clock speeds for higher bandwidth. You'll now find one or multiple microprocessors inside everything from the smallest devices to super-large mainframes. Inside a microprocessor are diodes, resistors, and transistors.

A CPU is based on an instruction set architecture (ISA). Two popular ones in the news currently are x86 and Arm. These essentially act as a blueprint of sorts for the CPU to handle the processing of instructions and how to interact with connected hardware. Cache is featured on a CPU and is used to store data for quick access. L1 is the smallest and fastest, followed by L2 and L3. If the data cannot be found in the cache, the CPU will move to random access memory (RAM).

A processor uses a clock signal to help keep everything synchronized. This signal is represented in CPU marketing and measured in hertz (Hz) and gigahertz (GHz). With all the millions of parts, high clock speeds, and millions of instructions, a considerable amount of heat is produced. This is why CPUs such as those from AMD and Intel have large heat spreaders. This part makes contact with a CPU cooler, which can be a simple heatsink or an all-in-one (AIO) liquid cooling block.

How the microprocessor came to be

It all started with Robert Noyce

In 1959, Robert Noyce invented the monolithic integrated circuit (IC) chip. Following the hybrid integrated circuit (hybrid IC) by Jack Kilby, the monolithic integrated circuit chip was used in hardware for the U.S. Air Force and National Aeronautics and Space Administration but later found its way into commercially available computers from IBM and other companies. The IC was responsible for exposing more people to personal computers but it wasn't until the microprocessor that things really took off.

Intel came out with the first single-chip microprocessor in 1971, the 4004. Based on a single MOS large-scale integration (MOS LSI) chip, these early processors were basic but could handle tens of thousands of instructions per second. Further development of the microprocessor allowed for more compact computers, which were interactive with operating systems. The Apple II, Commodore PET, and TRS-80 led the charge for the general public to acquire microcomputers. It was easier to obtain a PC with applications and games being developed.

Microprocessors started as 4-bit but grew to what we rely on today, 64-bit. This allows them to perform 64-bit operations and is far more powerful than what was possible with multiple IC boards before Intel came out with its general-purpose logic device, the Intel 4004. Today, you'll find a CPU inside billions of devices around the world. Everything from a smartwatch and television to a vehicle and airplane have microprocessors integrated for handling instructions, interacting with other hardware, and running software.

With technology today, you're able to pick up a portable device the size of a matchbox and enjoy a video call with someone thousands of miles away. Laptops have processors that can run video editing software and last for many hours on a single charge. Huge battery packs power electric vehicles and run feature-rich software to ensure you reach your destination safely and without further polluting the planet. The microprocessor is a marvel and one we take for granted along with many other technical advancements.