Manycore processor architectures

Trade-offs between performance and power have dominated the processor architecture landscape in recent times and are expected to exert a considerable influence in the future. Processing technologies ceased to provide automatic speedups across generations, leading to the reliance on architectural innovation for achieving better performance. Manycore processor systems have found their way into various computing segments ranging from mobile systems to the desktop and server space. With the advent of graphics processing units (GPUs) with a large number of processing elements into the computing space, manycore systems have become the default engine for all target computing domains. We have focused in this chapter on mainly the desktop and system-on-chip (SoC) domain, but the architectural possibilities blend in a seamless way into the other domains also. We outline a high-level classification of manycore processors and go on to describe the major architectural components typically expected in modern and future processors, with a focus on the computing elements. Issues arising out of the integration of the various components are outlined. Future trends are also identified.