Godson-3B: A 1GHz 40W 8-core 128GFLOPS processor in 65nm CMOS

As the latest product of Godson processor series, the Godson-3B processor is an 8-core high-performance general-purpose processor implemented in 65nm CMOS low-power general-purpose mixed process with 7 layers of Cu metallization. Godson-3B contains 582.6M transistors (including 4MB L2-cache) within 299.8mm 2 area. The number of signal pins in Godson-3B is 654. The highest frequency of Godson-3B is 1.05GHz, and the peak performance is 128GFLOPS (double-precision) or 256GFLOPS (single-precision) at 1GHz frequency with 40W power consumption. Godson-3B has an energy efficiency of 3.2GFLOPS/W. Other state-of-art high-performance processors have energy efficency of ∼1.3GFOPS/W (Westmere [2]) and ∼1.5GFLOPS/W (Power7 [3,4]). As shown in Fig. 4.4.1, Godson-3B contains 2 nodes while being able to scale to 16 nodes through inter-chip connection. Each node contains four cores, four L2-cache banks, one HyperTransport (HT) controller, one DDR2/3 controller, and the interconnection network connecting these components together. The interconnection network takes the 128-bit AXI standard interface with cache coherence extension.