Power management in an uncore fabric

In an example, a shared uncore memory fabric of a system-on-a-chip (SoC) is configured to provide real-time power management. The SoC may include a power management agent to inform the shared fabric that the processing cores and peripherals will be idle for a time, and to negotiate a power-saving state. The uncore fabric may also include a local power manager that detects when no access requests have been received for a time, such as when cores are operating from cache. The shared fabric may then unilaterally enter a power-saving state, and remain in that state until an access request is received. In the power-saving state, power and/or clocks are gated, and the fabric's state is stored in retention cells. When a new access request is received, an ungated controller may handle preliminary processing while the local power manager restores the state and powers up the shared fabric.