IBM 49Y1404 COMP 4GB DDR3-1333MHZ DRX8 1.35V UDIMMAddOn 4GB DDR3 SDRAM Memory Module For Server 4 GB (1 x 4GB) DDR3 1333 PC3 10664 DDR3 SDRAM 1333 MHz Dual rank Memory CL9 1. 35 V ECC Unbuffered 240 pin DIMM Lifetime Warranty VPN: 49Y1404 AM SKU: RSC241471 UPC: 821455287293 4 GB memory allows you to have more programs open at a time 1333 MHz speed to execute routine softwares at a steady pace DDR3 SDRAM interface multiplexes 2 bit data from memory cell and I O buses to minimize processor idle time