The new trends of memory semi-conductor technology are changing and developing. Phase-Change RAM (PRAM), Ferroelectric RAM (FeRAM), Magnetic RAM (MRAM) and Resistive RAM (RRAM) are going to take center stage of main memory material of new computer systems in next decade. PRAM also has higher dense, it can keep data about four times more than DRAM. But some problems caused when PRAM uses as a main memory directly. So we suggest Pre-load cache and Assistant buffer. It reduces main memory access and overcome low read speed of PRAM consequently. To reduce write operation also, we propose Assistant buffer. Assistant buffer keeps evicted data and impedes write operation, and facilitates more rapid response about required data when cache misses. As a result of our experimentation, overall performance is decrement of main memory accesses approximately 50 %.