ThermoStat project

Project Overview

Power densities and the implications of high operating temperatures on the failure rates of components are key driving factors of temperature-aware computing. Computer architects and system software designers need to understand the thermal consequences of their proposals, and develop techniques to lower operating temperatures to reduce both transient and permanent component failures. Until recently, tools for understanding temperature ramifications of designs have been mainly restricted to industry for studying packaging and cooling mechanisms, with little access to such toolsets for academic researchers. Developing such tools is an arduous task since it usually requires cross-cutting areas of expertise spanning architecture, systems software, thermodynamics, and cooling systems. Recognizing the need for such tools, there has been recent work on modeling temperatures of processors at the micro-architectural level which can be easily understood and employed by computer architects for processor designs. However, there is a dearth of such tools in the academic/research community for undertaking architectural/systems studies beyond a processor – a server box, rack or even a machine room. ThermoStat is a detailed 3-dimensional Computational Fluid Dynamics tool for thermal modelling of rack-mounted server systems. Example usage of this tool can be found.


Jeonghwan Choi (Ph.D Student at KAIST)
Youngjae Kim (Ph.D Student)
Anand Sivasubramaniam (Prof. in Dept. of Computer Science and Engineering)
Jelena Srebric (Prof. in Dept. of Architectural Engineering)
Qian Wang (Prof. in Dept. of Mechanical Engineering)
Joonwon Lee (Prof. in Dept of Computer Science, KAIST)


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CFD-based Tool for Studying Temperature in Rack-mounted Servers
Jeonghwan Choi, Youngjae Kim, Anand Sivasubramaniam, Jelena Srebric, Qian Wang, and Joonwon Lee
IEEE Transactions on Computer (TC), IEEE Press, August 2008.

Modeling and Managing Thermal Profiles of Rack-mounted Servers with ThermoStat
Jeonghwan Choi, Youngjae Kim, Anand Sivasubramaniam, Jelena Srebric, Qian Wang, and Joonwon Lee
Proceedings of the International Symposium on High Performance Computer Architecture (HPCA), February 2007. (28/174 = 16% accepted). Best student paper candidate.
Abstract     Paper

User Guidelines

ThermoStat is a thermal modeling tool for rack-mounted servers. The ThermoStat is based on CFD (Computational Fluid Dynamics) tools. Most academic institutions have licenses for popularly used CFD software such as FLUENT, FLOTHERM, Phoenics etc. Currently ThermoState is built on Phoenics (which is one of various CFD tools). ThermoStat provides useful tools for modeling and analyzing thermal behavior of rack-mounted servers and individual server.

How to create XML file for ThermoStat

In order to run ThermoStat, you need to create XML file for ThermoStat. This document contains information about how to write XML description of server/rack-mounted system. We define templates for the following components, such as rack, server, component, fan, inlet, finlet, size, position).

Demo File

A short video file has been prepared. It shows the users how to use ThermoStat and helps them to use it with ease. The below hyperlink will automatically play the video on your machine or you can directly download to view it.

Download ThermoStat

The current release version is version 0.9 because it need to be updated. The officially complete version is expected soon. If you would like to get the ThermoStat 0.9 Suit, please send a request to We will email you back a file named thermostat.tar.gz. Any comment regarding ThermoStat is welcome.

Copyright (C) of Computer Systems Laboratory, Department of Computer Science, The Pennsylvania State University, 2007