OWC 32GB (2x16GB) DDR3 1333 PC3-10600 CL9 ECC RDIMM memory upgrade

System-Specific DDR3 Kit

This 32 GB kit contains two 16 GB DDR3 1333 PC3-10600 CL9 registered ECC modules built for the Lenovo System x3950 X5. It targets administrators who need to expand memory capacity in that specific server platform. The modules operate at 1.5 V and carry the 2Rx4 organisation required by the system. They replace Lenovo part numbers 03X3813 and 0A89413.

Registered ECC Build

Each 240-pin RDIMM uses registered ECC circuitry, a design intended for workstation and server environments rather than standard desktops. The lack of a heat spreader keeps the profile low for dense chassis, while the registered buffer reduces electrical load on the memory controller. Mixing these modules with unbuffered memory is not supported, so the full population must follow the server's population rules.

Pre-Install Checks

Confirm the target machine is a Lenovo System x3950 X5 before ordering, as registered ECC DDR3 will not function in consumer desktop boards. Verify the system's qualified vendor list accepts 16 GB 2Rx4 modules at PC3-10600 speed and that the BIOS revision supports the total capacity you intend to install. Ensure all slots to be populated use identical registered ECC modules.