uncore一词，是英特尔用来描述微处理器中，功能上为非处理器核心（Core）所负担，但是对处理器性能的发挥和维持有必不可少的作用的组成部分。处理器核心包含的处理器组件都涉及处理器指令的运行，包括算术逻辑单元（ALU）、浮点运算单元（FPU）、一级缓存（L1 Cache）、二级缓存（L2 Cache）。Uncore的功能包括QPI控制器、三级缓存（L3 Cache）、窥探（内存一致性监测）管线（snoop agent pipeline）、内存控制器，以及Thunderbolt控制器。至于其余的总线控制器，像是PCI-E、SPI等，则是属于芯片组的一部分。

The uncore or system agent is a term used by Intel to describe the functions of a microprocessor that are not in the core, but which must be closely connected to the core to achieve high performance. It has been called "system agent" since the release of Sandy Bridge Intel microarchitecture. The core contains the components of the processor involved in executing instructions, including the ALU, FPU, L1 and L2 cache. Uncore functions include QPI controllers, L3 cache, snoop agent pipeline, on-die memory controller, and Thunderbolt controller. Other bus controllers such as PCI Express and SPI are part of the chipset.