TILTS: A Fast Architectural-Level Transient Thermal Simulation Method

As power density of microprocessors is increasing rapidly and resulting in high temperatures, the reliability of chips is greatly affected, making thermal simulation a necessity for CPU designs. Current thermal simulation methods (for example, the HotSpot simulator) are very useful, but are still inefficient when performing thermal analysis for long simulation times. In this paper, we propose a novel transient thermal simulation method for CPU chips at the architecture level, TILTS (Time Invariant Linear Thermal System), which utilizes the fact that the input power trace is discretized over a fixed sampling interval to accelerate thermal simulations. TILTS allows us to calculate transient temperatures on a chip over long simulation times. Based on a linear system formulation, TILTS has the same accuracy as that of traditional thermal simulation tools and is orders of magnitude faster than previous algorithms. Compared to the HotSpot simulator, TILTS achieves speedups of 1300 for the processors in our experiments for an appropriate sampling interval of 100 s. With some additional memory space, the improved algorithm CONTILTS (Convolutional TILTS) is about 6000 times faster than the HotSpot simulator for the processors in our experiments.