This document provides an overview of the AMD EPYCTM microprocessor architecture. It discusses the key tenets of the EPYC processor design including the "Zen" CPU core, virtualization and security features, high per-socket capability through its multi-chip module (MCM) design, high bandwidth fabric interconnect, large memory capacity and disruptive I/O capabilities. It also details the microarchitecture of the "Zen" core and how it was designed and optimized for data center workloads.