An Improved Block-Based Thermal Model in HotSpot 4.0 with Granularity Considerations

This technical report describes our most recent improvements to the HotSpot thermal model. First, in response to a previous paper in WDDD 2006 [1] that cites some accuracy shortcomings, we improve treatment in HotSpot’s “block model” of high aspect-ratio blocks, high power densities, and convection boundary conditions. These improvements are included in the newest release of the HotSpot software, version 4.0.1 Second, to help guide users’ modeling efforts and choice of modeling resolution, we propose an analytical approach to find the relationship between the power modeling granularity and the associated peak temperature rise at that granularity, i.e. the relationship between the size and peak temperature of a uniform heat source. We theoretically confirm the existence of a strong spatial temperature low-pass filtering effect: a tiny heat source is much cooler than a large heat source with the same power density.