ECC REGISTERED UPGRADE: This type of memory is used in Workstations and Servers. It will NOT be compatible with standard desktop computers. Also, it cannot be mixed with UNBUFFERED -or- ECC LOAD REDUCED memory. OWC 64GB DDR5 4800 PC5-38400 CL40 2Rx4 288-pin 1.1V ECC Registered DIMM Memory RAM Module Upgrade, compatible with Hynix part numbers HMCG94AEBRA, HMCG94MEBQA109N, HMCG94MEBQA112N, HMCG94MEBQA121N and HMCG94MEBQA123N. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. MAXIMIZE YOUR SERVER: With OWC's ECC Registered Server Memory, you will extend the life of your old infrastructure or save money when building a new one. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing.