memory type used 2004–2008, commonly known by names ranging from DDR2-400 / PC2-3200 through DDR2-1200 / PC2-9600. DDR3 DDR3 SDRAM (Double Data Rate 3)  240-pin SDRAM memory type used 2008–current, commonly known by names ranging from DDR3-800 / PC3-6400 through DDR3-2000 / PC3-16000. DIMM DIMM Dual In-line Memory Module.  168-pin SDR