Abstract: A programmable multithreaded Vertex Processor is designed for 3D graphics rendering in embedded applications.The Single Instruction Multiple Data (SIMD) architecture is proposed, so four single precision floating-point numbers are processed simultaneously.The multithreaded datapath supports parallel execution of four threads, so the pipeline stalls are reduced when data hazards occur and the processing efficiency rises up.The proposed four-threaded Vertex Processor achieves 2.1~2.8 times of performance improvement at a relatively small hardware cost compared to the single-threaded architecture.The Vertex Processor supports OpenGL ES 1.1 and Vertex Shader Model 1.1.Implemented in 90nm CMOS process, it achieves 50 Mvertices/s of geometry performance at the operating frequency of 200MHz.