Samsung has introduced its first 256GB memory module for future servers. The new module, registered as RDIMM, is based on Samsung’s 16Gb DDR4 memory devices introduced earlier this year and takes advantage of the company’s 3DS (three-dimensional stacking) packaging.
The new module will offer higher performance and lower power consumption than the two 128GB LRDIMMs that are currently in use. Samsung’s 256GB DDR4 Registered DIMM with ECC carries 36 8GB (64Gbit) capacity memory packs, along with the IDT 4RCD0229K registration chip, for storing address and command signals and increasing the number of areas supported by a memory channel. The enclosures are based on four components of a single 16GB nozzle connected by silicon tracks (TSV). From an architectural point of view, the 256 GB module has an octal classification because it has two physical and four logical areas.
These new DIMMs are registered DIMMs (RDIMMs) and not reduced load DIMMs (LRDIMMs), which is very interesting to note. Typically, LRDIMMs are required for high-capacity configurations, where these stylish DIMMs use an additional buffer that affects power consumption and latency compared to RDIMMs.
Future Intel Xeon Cascade Lake processors seem to support up to 3.84TB of memory in the 12 DIMM slots, so installing 12 256GB RDIMMs could give a dual socket server 6TB of storage space. AMD’s existing EPYC processors officially support up to 128GB of LRDIMM memory modules and up to 2TB of total memory, something that is logical as AMD RDIMM has not yet validated 256GB. If AMD believes that 256 GB RDIMMs are suitable for your platform, you can support them by adapting the microcode of your existing EPYC processors or simply validating them with your next 7nm EPYC “Rome” CPU.
Samsung has not revealed the exact specifications of its 256GB RDIMM, although it does not expect its frequency to be significantly higher than the current DDR4-2400 and DDR4-2667 speeds.