NEMIX RAM 256GB (4x64GB) DDR5 5600 ECC RDIMM CL46 1.1V 2Rx4 288-pin Lenovo SR780a V3 memory upgrade

256GB DDR5 5600 ECC RDIMM kit

This NEMIX RAM kit supplies 256GB across four 64GB registered DDR5 modules rated at 5600 MT/s with CL46 latency. It is built for the Lenovo ThinkSystem SR780a V3 rack server and carries ECC protection for data integrity in enterprise workloads. The modules run at 1.1V and use a 2Rx4 organisation on a 288-pin form factor. Buyers needing non-ECC memory or consumer DIMM slots cannot use this kit.

Installation and common issues

The modules are keyed 288-pin DDR5 RDIMMs that seat in the server’s registered DIMM slots; alignment is straightforward when the ejector levers are open. Because the kit is registered and ECC, the system BIOS must support registered memory or the server will not post. Mixing these sticks with unbuffered or different-rank modules typically causes boot failure or reduced stability. Always follow the Lenovo service guide for population order and firmware updates.

DDR5 RDIMM practical limits

DDR5 RDIMM topology relies on the memory controller’s registered clock driver, so maximum capacity and speed depend on the CPU’s supported ranks per channel. The 2Rx4 organisation counts as two ranks per module, which can limit the number of DIMMs per channel at the rated 5600 MT/s. Voltage is fixed at 1.1V, so no manual over-voltage tuning is available on locked server platforms.