The high performance chip design on H.264/AVC integer motion estimation is presented in this paper to satisfy the requirements from real-time HDTV video applications. Using a novel multi-chip architecture named System in Silicon (SiS), core ASIC and external DRAMs which are designed in different design rules are integrated onto a single chip to achieve the significantly wide word-width of 1024 bits and band-width of 25Gbps in logic-memory communication. In core's design, 2D PE array is adopted to avoid the broadcast signals which limit the circuit's speed and the delay registers which prevent the full hardware utilization. As the implementation, this chip is fabricated with 0.18μm technology (core) and 0.11μm technology (DRAM). The core size is 14.1×7.1 mm2, it contains 1966.1K logic gates and 22.5KB SRAM. It can work at the high operating clock frequency up to 200MHz and can process more than 263K macro blocks within one second. It is suitable to the application of HDTV video streams (1920×1088) at real time (30fps) and can be a useful part of multimedia system.