vCPU is a portion of a physical CPU allocated to a virtual machine.
A virtual CPU represents a portion of the underlying physical CPU resources assigned to a virtual machine (VM). Different cloud providers handle vCPU allocation differently. AWS calls them vCPUs, Azure refers to them as virtual cores, and Google Cloud uses both terms. vCPUs are typically implemented using hyperthreading, where one physical CPU core can run two vCPUs. The performance of a vCPU can vary based on the instance type and generation. Cloud providers often use Intel Xeon or AMD EPYC processors, with newer generations offering better performance per vCPU. When selecting instance types, it’s crucial to consider both the number of vCPUs and their underlying hardware generation to ensure optimal performance for your workload.
