RamCity guarantee the above Kingston 2GB 240-pin DIMM is fully compatible with your IBM/Lenovo x Series System Server x3850 X5.
This is a genuine Kingston Memory component, and is backed by a Lifetime replacement warranty against defects.
Many other memory module companies use a generic module for a variety of systems, and may encourage you to purchase a cheaper module for your system. Kingston takes design to a higher level and manufactures system specific memory.
This means the design is customized to meet the strict memory specifications that IBM/Lenovo insist upon. The design is fine-tuned to match the timing of the x Series System Server x3850 X5 model, to reduce noise and heat, and allow for the most efficient communication between the memory and the CPU. Kingston also tests the module in the system using popular applications, operating systems and the original equipment manufacturer's diagnostic program.