A CPU core is an independent processing unit within a central processor. It integrates its own arithmetic logic units (ALU), registers, and Level 1 (L1) cache. Modern CPUs combine between 2 and 128 physical cores on a single silicon die, enabling hardware-level parallel execution of multiple tasks.
Each core fetches instructions from RAM, decodes them, and executes data operations. Multithreading technologies, such as Hyper-Threading or SMT, allow a single physical core to handle two logical threads simultaneously, maximizing execution unit utilization and reducing pipeline stalls.
Usage and Performance
The number of cores determines a system's capacity for parallel processing. In server workloads like PostgreSQL databases or KVM hypervisors, high core counts are prioritized to handle numerous concurrent requests. In video editing and 3D rendering applications, increasing the core count directly reduces operation time.
For instance, an AMD EPYC 9654 processor features 96 physical cores. This allows for deploying hundreds of isolated microservices on a single physical node without performance degradation caused by excessive context switching.