Thermal management in Windows

Provides information about how Thermal management in Windows plays a key role in delivering PCs that have good performance and are safe to use — even when they are running a high-energy workload.

PCs are becoming more mobile and compact, making hardware design for thermal dissipation more challenging. At the same time, users' expectations for performance and capabilities continue to grow, increasing the heat generation of system components. Good thermal design is now more important than ever. The Windows thermal management framework offers a software solution that complements the hardware design. This infrastructure gives system designers a simple way to dictate how each component of the system reacts to thermal conditions. The control mechanisms in this framework rely on the thermal management policies defined by the system designer for a particular hardware platform. Starting with Windows 8.1, this framework is included as part of the operating system in every Windows PC. This document describes the Windows thermal management user experience and provides recommendations and guidance to system designers for how to deliver that experience using the Windows thermal management framework or through proprietary solutions. For more information, see Device-Level Thermal Management.

Principles of thermal management

Ideally, all system components in a PC should operate at peak performance while never getting too hot. In fact, no PC can operate this way. To be fully functional, all system components consume power in order to operate, and power produces heat. A PC must be prevented from overheating so that it operates reliably and is comfortable to touch. The goal of Windows thermal management is to limit the heat generated by the PC, but to do so in a way that minimally interferes with or detracts from the user experience.

Windows thermal management is based on these five principles:

  • Safety – Regardless of workload or external conditions, the PC never becomes unsafe for a user to handle.
  • Operating range – The PC operates over the normal operating range of ambient temperatures.
  • Full-performance experiences – Core Windows experiences are not performance-compromised under normal operating conditions.
  • Quiet while idle – While the PC is in a low-power state such as Modern Standby, users should not see the fan turn on under any circumstances.
  • Diagnosability – Windows prefers any thermal mitigation measures (passive and active cooling modes) to be initiated through mechanisms that are provided by the operating system so that issues can be identified in the field and reported back via telemetry.

The following topics provide more information about the datatypes and IOCTLs used in Thermal management, along with some examples.

In this section

Topic Description

Design Guide

This PC thermal management design guide provides information about how to determine the PC temperature values that are "too hot" and "too cold."

User Experience

From a thermal point of view, the user experience should be such that the user can operate the PC for as long as possible without interruption. And the user should only be notified of thermal problems, when the PC can no longer operate.

Examples, Requirements and Diagnostics

This topic presents examples of thermal management issues, and also discusses requirements and diagnostic methods.

Thermal Management Datatypes

This topic discusses the datatypes that are used for Thermal Management in Windows.

Thermal Management IOCTLs

This topic discusses the input/output controls (IOCTLs) that are used for Thermal Management in Windows.