A calibration based thermal modeling technique for complex multicore systems

A calibration based method to construct fast and accurate thermal models of the state-of-the-art multicore systems is presented. Such models are usually required during Design Space Exploration (DSE) exercises to evaluate various task-to-core mapping, associated scheduling and processor speed-scaling options for their overall impact on the system temperature. Current approaches require modeling the thermal characteristics of the target processor using numerical simulators, which assume accurate information about several critical parameters (e.g., the processor floorplan). Such parameters are not readily available, forcing the system designers to use time and cost intensive, and possibly error-prone techniques such as using heat maps for reverse-engineering such parameters. Additionally, advanced power and temperature management algorithms commonly found in the state-of-the-art processors must also be accurately modeled. This paper proposes a calibration based method for constructing the complete system thermal model of a target processor without requiring any hard-to-get information such as the detailed processor floorplan or system power traces. Taking an example of a sufficiently complex Intel Xeon 8-core processor, we show that our approach yields an accurate thermal model, which is also lightweight both in terms of memory and compute requirements to be practically feasible for DSE over current processors.