How do CPUs Work? Exploring the 💻🧬 DNA of the Digital World

How do CPUs Work? Exploring the 💻🧬 DNA of the Digital World with tags cpu, computers, processor, integrated circuit, computer chips, inside a computer, computer engineering, computer, cpu architecture, hardware, digital, digital dna, cpus, central processing unit, central processing units, apple, apple2e, macbook pro, macbook, laptop, desktop, computer hardware, desktop computer, intel, arm, amd

Have you ever wondered how CPUs work? Well, in this video, we take a 3D animated tour of a Central Processing Unit and see exactly how it works. Central Processing Units, or CPUs, are incredibly complicated, and they practically run the modern world. CPUs can be found in every desktop computer, laptop, video game console, smartphone, and any other device you use on a daily basis. CPUs are built from tens of billions of transistors assembled into billions of logic gates, and essentially they're amazingly powerful calculators. But in reality, they're more like instruction-crunching and data-moving machines. All CPUs share a common DNA, which is the Fetch-Decode-Execute cycle. This cycle is both very powerful and a critical limitation of every CPU. So dive right in and we'll show you how CPUs work.

Table of Contents for How CPUs Work

00:00 - The CPU Inside Your Computer

01:45 - The Technological DNA of CPUs

03:28 - Teardown of a Laptop

04:39 - A CPU Die

05:59 - Analogy of a CPU

07:10 - Explaining the CPU Analogy

09:47 - How do CPUs Complete Instructions?

12:34 - The Program Counter

13:33 - Loops and Branches

16:01 - All Possible Instructions

17:07 - Fetch Decode Execute

21:14 - CPU Clock and Fetch Decode Execute

22:53 - Uncovering the Technological DNA: Fetch Decode Execute

23:47 - ASICs and FPGAs

24:35 - Memory and Writeback

25:36 - Sponsored Section

28:02 - RISC vs CISC

30:09 - About Branch Education

31:09 - Extrapolating to the M1

33:36 - The Diagram of a Performance Core

34:09 - CPU vs SoC

34:58 - GPU Architecture

35:55 - Thank You to Our Supporters

We're working on more ambitious subjects like How AI Works

Animation Director: Mike Radjabov

Primary Animators: Muazzam Azizova, Max Botirov

Secondary Animators: Parvesh Khatri, Sherdil Davronov

Research, Script and Editing: Teddy Tablante

Twitter: @teddytablante

Modeling: Prakash Kakadiya

Image and Thumbnail Editing: Randy Catequista, BJ Torrejos, Adam Silven

Voice Over: Phil Lee

Sound Design by Drilu: www.drilu.studio

Sound Design and Mix: Luis Huesca

Erratum:

4004 (dot) com. "Intel 4004 - 50th Anniversary Project

Apple Newsroom. "Apple Unleashes M1" Nov10, 2020

ARM Information Center. "ARMv8 Architecture Reference Manual"

Compiler-explorer (dot) com. "Compiler Explorer"

Ken Shirriff's blog. "The 6502 microprocecssor chip"

Visual6502 (dot) org. "Visual Transistor-levl Simulation of the 6502 CPU"

Wikipedia contributors. "Control Unit", "CPU", "Instruction Register", "Integrated Circuit", "Memory Address Register", "Program Counter". Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, Visited November 11th 2025

WikiChip. "Cortex A77 Microarchitecture"

#CPU #CompSci #HowItWorks