Wintec ONE MHzCL9 12GB(3x4GB) UDIMM Kit 1.5V with HS 12 Triple Channel Kit DDR3 1333 (PC3 10600) 240-Pin SDRAM 3OH13339U9H-12GT 3 memory modules; these three modules divides the number of system tasks equally among themselves Each module is a 4GB DDR3 1333MHz memory; each module delivers outstanding performance by itself Combined memory of 12GB; the ultra-large memory can accommodate any number of system tasks that you want to run