Multi-core server processors thermal analysis

To improve computing performance for server systems, increase in the number of CPU cores is one of the primary design parameters, in addition to higher frequency and advanced process technology node adoption. CPU core count, size, physical distribution and power density on the processor die could have great impact on thermal and computing performance. A thermal analysis is performed to understand these effects with the modeling assumptions: 60 mm × 60 mm flip chip lidded package, single die at size of 25 mm × 25 mm and total power dissipation of 300W. The thermal model including package and heat sink is set up to analyze variables such as core count, distribution and power level/density. To keep the processor temperature from exceeding the junction limit, dynamic voltage and frequency scaling (DVFS) is commonly used. A method to correlate thermal and computing performance based on DVFS, is also explored when junction temperature hits the limit. The impact of multi-core processor design on thermal performance is translated into the impact on computing performance under thermal constraints. Thermal guidance on multi-core processor die floor plan to optimize computing performance is provided.