This paper proposes new models of GPU energy consumption from the perspectives of hardware architects and graphics programmers by performing an architecture-independent analysis of the classical graphics rendering pipeline which is still in widespread use today. The detailed analysis includes graphics rendering workload, memory bandwidth and energy consumption . Although the models are derived from classical 3D pipeline, they are extensible to programmable pipelines. There are many factors that affect the performance and energy consumption of 3D graphics rendering, such as the number of textures, vertex sharing, level of details, and rendering algorithms. The proposed models are validated by our simulation study and used to guide our 3D graphics hardware design and 3D graphics programming in order to optimize performance and energy consumption of our GPU prototypes which have been successfully fabricated in SMIC 0.13μm CMOS technology.