What scientists must know about hardware to write fast code

This document is hosted at https://viralinstruction.com/posts/hardware/

It is written as a Pluto notebook. If you can, I recommend running the code in a Pluto notebook so you can play around with it and learn. Alternatively, you can read the HTML file in your browser.

PRs are welcome.

This notebook covers:

• Why you must limit your disk read/writes
• What a CPU cache is, and how to use it effectively
• Memory alignment
• How to read assembly code and why you must do it
• Why you should reduce allocations
• Why immutable datastructures usually are fastest
• SIMD vectorization
• Struct of arrays vs array of structs
• Specialized CPU instructions
• Function inlining
• Loop unrolling
• Branch prediction
• The effects of memory dependencies in the CPU pipeline
• Multithreading
• Why GPUs are fast at some things and slow at others