Chapter 1, Julia is Fast, discuses some of the design underpinning the language and its focus on high performance.
Chapter 2, Analyzing Julia Performance, provides the tools and techniques you can use to measure and analyze the performance of your own programs.
Chapter 3, Types in Julia, describes the type system and discusses why writing type-stable code is crucial to high performance.
Chapter 4, Functions and Macros – Structuring Julia Code for High Performance, discusses techniques to use dispatch and code generation to structure high-performance programs.
Chapter 5, Fast Numbers, discusses the basic numeric types and why they are fast.
Chapter 6, Fast Arrays, describes ways to use multidimensional arrays in the fastest possible way.
Chapter 7, Beyond the Single Processor, provides an introduction to Julia's distributed computing facilities.