This Cisco® MEM-4400-4GU8G compatible 8GB (2x4GB) factory original DRAM upgrade is 100% guaranteed to be compatible with your system and to work right the first time. All of our server memory is built to strict JEDEC standards at one of the tier 1 facilities (Samsung, Micron, or Hynix). Our products are also guaranteed by federal law to not affect or void OEM warranties.