Temperature-Aware Microarchitecture

K. Skadron, M. R. Stan, W. Huang, S. Velusamy, K. Sankaranarayanan, and D. Tarjan.
In Proceedings of the 30th International Symposium on Computer Architecture, pp. 2-13, San Diego, CA, June 2003.

With power density and hence cooling costs rising exponentially, processor packaging can no longer be designed for the worst case, and there is an urgent need for runtime processor-level techniques that can regulate operating temperature when the package's capacity is exceeded. Evaluating such techniques, however, requires a thermal model that is practical for architectural studies.

This paper describes HotSpot, an accurate yet fast model based on an equivalent circuit of thermal resistances and capacitances that correspond to microarchitecture blocks and essential aspects of the thermal package. Validation was performed using finite-element simulation. The paper also introduces several effective methods for dynamic thermal management (DTM): "temperature-tracking" frequency scaling, localized toggling, and migrating computation to spare hardware units. Modeling temperature at the microarchitecture level also shows that power metrics are poor predictors of temperature, and that sensor imprecision has a substantial impact on the performance of DTM.

Awarded the Bob Rau memorial award for best student paper at ISCA.

(This paper partially supersedes the work presented in our Microelectronics Journal paper)

This ISCA paper is available in ps and pdf
Powerpoint slides (as PDF) from our ISCA presentation are also available.
An extended technical-report version is also available

HotSpot software home page