The x86-64 Architecture
Part of the Fundamentals section of Coddy's Assembly journey — lesson 6 of 45.
An architecture is the design of a CPU. Different CPUs have different architectures, just like different cars have different engine designs.
In this course, you are learning x86-64 — the architecture used by most desktop computers, laptops, and servers.
Why is it called x86-64?
| Part | Meaning |
|---|---|
| x86 | The family name (from Intel 8086, 80286, 80386, 80486...) |
| 64 | The register size (64 bits) |
Other names for the same thing:
- x86-64
- x64
- AMD64
- Intel 64
All mean the same architecture you are learning.
What does 64-bit mean?
- Each register can hold 64 bits of data
- The CPU can process 64 bits at a time
- Memory addresses are 64 bits wide
Different architectures use different register names:
| Architecture | Register names |
|---|---|
| x86-64 (this course) | rax, rbx, rcx, rdx, rsi, rdi |
| ARM (phones, tablets) | x0, x1, x2, x3... |
| RISC-V (open source) | a0, a1, a2, a3... |
The same instruction (put 5 into a register) looks different on each architecture:
| Architecture | Code |
|---|---|
| x86-64 | mov rax, 5 |
| ARM | mov x0, #5 |
| RISC-V | li a0, 5 |
Important: The concepts you learn (registers, memory, instructions) apply to all architectures. Only the names and syntax change.
Try it yourself
This lesson doesn't include a code challenge.
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Fundamentals
1The Machine
What is CPUMemoryRegisters vs MemoryHow instructions workTwo-File PatternThe x86-64 Architecture