Research On The Techniques Of Thermal Control For Multi-core 3D Processor With Interlayer Cooling

In the early development stage of microprocessor,the frequency doubled year by year to achieve higher performance,which also cause the power consumption and temperature of microprocessor increased,and the air cooling technology used is close to its heat flux limit.Therefore,the frequency of microprocessor is no longer increasing significantly after 2004,and the architecture of microprocessor developed from single-core to multi-core gradually,to improve performance by parallelism.But with the increase in the number of cores,the problems called "Storage Wall" and "Bandwidth Wall" due to wire delay have become more severe.With the emergence of threedimensional integrated circuit technology,the microprocessors obtain a new way to enhance performance.However,an important challenge for 3D ICs is cooling problem.Only a few commercial chips can realized with 3D integration,with lower power consumption,such as memory chips.The thermal accumulation problem of high-performance chips caused by 3D integration cannot be resolved by the traditional air cooling technology.Inter-layer microchannel cooling technology is considered an effective solution to solve the thermal problems of three-dimensional integrated circuits,which can provide a higher cooling coefficient than traditional cooling technology.In this paper,the main content researched is the optimized capability of thermal control for three-dimensional stacking microprocessors with inter-layer cooling.The main optimization target is to reduce the thermal emergency events and the difference of internal thermal distribution in microprocessor.The relevant indexes include maximum temperature,average temperature and thermal gradient.Based on the analysis and establishment of the thermal model for threedimensional multi-core microprocessor with inter-layer cooling,the research,experiment and result analysis of the microprocessor thermal optimization mechanism are discussed respectively including task allocation and floor-planning.The main work and innovation of this paper are as follows:1.The study on the thermal model of 3D multi-core microprocessor with interlayer cooling.A thermal model of 3D multi-core microprocessor with inter-layer cooling is proposed,which is called TM-3DICool,based on the traditional thermal evaluation model of microprocessors in traditional integrated technology.The generation and propagation characteristics for thermal of the microprocessor including the inter-layer cooling system are analyzed respectively from the solid thermal model and the liquid thermal model,which can support the following optimization design of the microprocessor thermal management.2.The study on the thermal optimized task allocation technology of 3D multi-core microprocessor with inter-layer cooling.Based on the simulated annealing optimization method,a thermal optimized task allocation technique,TASA-3DICool,is proposed for 3D multi-core microprocessors with inter-layer cooling.The "99%" power consumption is defined to characterize the difference between the normal and extreme working conditions of the microprocessor.The thermal optimized task allocation technique takes into account the normal and extreme working conditions for the tasks in microprocessor.In the thermal optimized allocation technique,the maximum temperature and maximum temperature gradients under both working conditions have a better balance.3.The study on the technique of thermal optimized floor planning technique for 3D multi-core microprocessors with inter-layer cooling.Based on the particle swarm optimization(PSO)method,a thermal optimized floor planning technique for 3D multi-core microprocessors with inter-layer cooling is proposed,which is called FPPSO-3DICool.The thermal optimized floor planning is to reduce the thermal accumulation,and the particles in particle swarm optimization method is to close the cold and avoid the hot locations,which is fitted to the thermal optimized floor plan to reduce the maximum temperature and maximum temperature gradient within the microprocessor.Compared with the experimental results obtained by the commonly used floor planning mechanisms,the FPPSO-3DICool has strong ability of temperature control and thermal balance,especially when the number of cores is large,and the floor planning space is limited.