The three-dimensional (3-D) stacking memory is good way to extend the local memory of embedded CPU and/or DSP by the through-silicon-vias (TSVs) technology. In this work, we show a multi-core system with 3-D stacking memory, and the stacking memory can be configured as instruction cache or local data memory for each DSP core. Due to the non-cacheable property of local memory, the programmers have to rethink the software algorithm and the data structure to efficiently use the extended memory space. To demonstrate the performance enhancement of 3-D system, this paper presents three enhanced multimedia applications for HW/SW co-simulation by the electronic system-level (ESL) virtual platform. According to the experimental results, the 3-D system performance can be improved by 30%~50% for assembly coded single-channel H.264 decoder and multi-channel H.264 decoder respectively, compared with traditional 2-D system. In addition, for a JPEG decoder compiled with C compiler, more than 6 times system performance can be improved by placing the data section, heap and stack structure from external DDR2 memory to the 3-D stacking memory.