Computer Architecture and High Performance provides a practical, evidence-driven approach to understanding modern computer systems. It connects instruction set architecture, microarchitecture, memory hierarchies, caches, pipelines, parallelism, multicore systems, accelerators, performance measurement, and system-level optimization. Through worked scenarios, architectural models, and diagnostic methods, the book shows how hardware behavior, workloads, and measurements interact—and how to distinguish architectural guarantees from implementation-specific performance. Designed for students, software engineers, systems practitioners, and technically curious readers, it emphasizes careful reasoning, measurable evidence, and repeatable performance analysis.