PCI Express* Architecture Power Management

PCI Express* Architecture Power Management Rev 1.1

This paper presents power management guidelines for PCI Express links on Intel-based Mobile platforms. It describes the mapping from platform sleeping states and device power states to link power states, including the procedure to support Mobile-specific S1/POS and CPU C3/C4 scenarios. Device and platform power saving opportunities are identified for each link power state. L1 entry policy is also recommended to optimize device power. Several power optimization techniques are described, including minimizing flow control updates and acknowledgement packets to improve bandwidth efficiency, and pipelining packets to increase opportunities for active state link power management. These power management guidelines enable architectural innovation to achieve power-optimized interconnect performance.

Purpose of the document and target audience: This document is a collection of guidelines and recommendations for Intel-based Mobile PC platforms with PCI Express interconnect technology. The intent is to provide information that will improve PCI Express architecture enabled notebook performance while at the same time minimizing power consumption to reduce thermal problems and to maximize battery life. This is by no means intended to be a comprehensive description of all possible optimizations. It is also not intended to be used as a standard or specification. The target audience for this document is architects, engineers, and system developers whose role is to develop devices or systems incorporating PCI Express technology.

Read the full PCI Express* Architecture Paper.