OWC 16GB DDR5 4800 CL40 1Rx8 288-pin 1.1V ECC RDIMM 4R8D51R816GB

Server ECC RDIMM upgrade

This 16 GB DDR5 4800 CL40 registered DIMM is built for Lenovo ThinkSystem SR675 V3, SR850 V3, SR860 V3 and ST650 V3 servers. It delivers ECC error correction and registered buffering for stable operation in multi-socket workloads. The module runs at 1.1 V and follows JEDEC PC5-38400 timing. Buyers using standard desktop boards or unbuffered memory cannot use this part.

Simple slot install, no mixing

Installation is a standard 288-pin DIMM insertion; power down, open the chassis, seat the module until the latches click, then power on. The critical mistake is mixing this registered ECC stick with unbuffered or load-reduced DIMMs — doing so prevents boot or causes data errors. Follow the server vendor's population rules for rank and channel balance. No heat spreader is fitted, so airflow across the PCB is required.

Verify model and slot rules first

Confirm the exact ThinkSystem model matches SR675 V3, SR850 V3, SR860 V3 or ST650 V3 before ordering. Check the system service guide for maximum DIMMs per processor, supported ranks per channel and whether 1Rx8 modules are allowed in your planned configuration. Ensure the BIOS is current enough for DDR5 4800 registered memory. This module replaces Lenovo part numbers 4X71L72498, 4X77A77029 and 4X77A81437.