Accurate Power Density Map Estimation for Commercial Multi-Core Microprocessors
Jinwei Zhang, Sheriff Sadiqbatcha, Wentian Jin and Sheldon X.-D. Tan
Electrical and Computer Engineering, University of California, Riverside, CA 92521
ABSTRACT
In this work, we propose an accurate full chip steady-state power density map estimation method for the commercial multi-core microprocessors. The new approach is based on the measured steady-state thermal maps (images) from an advanced infrared (IR) thermal imaging system to ensure its accuracy. The new method consists of a few steps. First, based on the first principle of heat transfer, 2D spatial Laplace operation is performed on the given thermal map to obtain the so-called raw power density map, which consists of both positive and negative values due to the steady-state nature and boundary conditions of the microprocessors. Then based on the total power of the microprocessor from an online CPU monitoring tool, we develop a novel scheme to generate the actual real positiveonly power density map from the raw power density map. At the same time, we develop a novel approach to estimating the effective thermal conductivity of the microprocessors. To further validate the power density map and the estimated actual thermal conductivity of the microprocessors, we construct a thermal model with COMSOL, which mimics the real experimental set up of measurement used in the IR imaging system. Then we compute the thermal maps from the estimated power density maps to ensure the computed thermal maps match the measured thermal maps using FEM method. Experimental results on intel i7-8650U 4-core processor show 1.8°C root-mean-squareerror (RMSE) and 96% similarity (2D correlation) between the computed thermal maps and the measured thermal maps.
