NVDIMM

A Non-Volatile Dual In-line Memory Module (NVDIMM) is a random-access memory for computers. "Non-volatile" means that the memory retains its contents even when electrical power is removed either from an unexpected power loss, system crash, or normal shutdown. "Dual in-line" identifies the product as using the DIMM package. NVDIMMs improve application performance, data security, and system crash recovery time. They enhance SSD endurance and reliability.

"Non-volatile" products may use volatile memory during normal operation and dump the contents into non-volatile memory if the power fails, using an on-board backup power source. Volatile memory is faster than non-volatile; it is byte-addressable; and it can be written to arbitrarily, without concerns about wear and device lifespan. However, including a second memory to achieve non-volatility (and the on-board backup power source) increases the product cost compared to volatile memory.

There are three types of NVDIMM implementations by JEDEC Standards org:

Non-Standard NVDIMM implementations:

As of November 2012, most NVDIMMs used NAND flash as the non-volatile memory. Emerging memory technologies aim to achieve NVDIMM without a cache or two separate memories. Intel and Micron have announced use of the 3D XPoint non-volatile memory technology in NVDIMMs, and Sony and Viking Technology have announced an NVDIMM-N product based on the ReRAM technology.

NVDIMMs evolved from the BBU (battery backed up) DIMM, which used a backup battery to sustain power to a volatile memory for up to 72 hours. However, batteries are disfavored in computer components because they have a limited lifespan, they may be regarded as hazardous waste, and they contain heavy metals which violate RoHS compliance.

When the module includes non-volatile memory, on-board backup power is only required for a short time after the computer's power fails. Therefore, modern NVDIMMs use supercapacitors to store energy.

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