2 x 2 gig sticks, ddr2 , DDR2 1200/1066/800/667 Non-ECC,Un-buffered Memory
Dual Channel memory architecture is my requirement my current ram specs

Memory
    Type    DDR2
    Size    4096 MBytes
    Channels #    Dual
    DRAM Frequency    399.5 MHz
    CAS# Latency (CL)    5 clocks
    RAS# to CAS# Delay (tRCD)    5 clocks
    RAS# Precharge (tRP)    5 clocks
    Cycle Time (tRAS)    18 clocks
    Command Rate (CR)    2T