Emerging technologies: Non-Volatile Memory

The memory technologies that dominate the computing industry today are, DRAM and NAND flash; but it should be noted that both of these technologies have their pros and cons. DRAM delivers the highest performance (latency / speed), with practically infinite endurance, yet it is volatile and has much lower capacity points than other memories (i.e NAND flash). NAND flash, on the other hand, scales to high capacity and is non-volatile, relatively cheap ($/Gbit) but is significantly slower than DRAM. Additionally NAND flash endurance and data retention are getting worse as process geometries continue to shrink, meaning that for write intensive enterprise applications, NAND flash, in the long term, may well not be an optimal memory technology.

What is a Non-Volatile DIMM (NVDIMM)?

A DDR3 / DDR4 NVDIMM, is a module that can be integrated into the main memory of an industry standard compute platform (i.e. server), perform workloads at DRAM speeds, yet be persistent & provide data retention in the event of a power failure or system crash.

Viking Technology’s ArxCis-NV™, a non-volatile DIMM, is a memory subsystem that combines the speed and endurance of DRAM, together with the non-volatile data retention properties of NAND flash. This marriage of DRAM and NAND technology delivers a high speed and low latency “non-volatile / persistent” memory module. Designed from the ground up to support unlimited read/write activity, it performs at fast DDR3 speeds (with DDR4 speeds coming soon)and can sustain itself from host power failure or a system crash. This solution can be viewed as the first commercially viable “Storage Class Memory” for the enterprise market.

What makes this module different from standard DRAM modules is that, in the event of a power failure or system crash, the data in the NV-DIMM is securely preserved and available almost immediately upon power being restored to the host system (suspend/resume).

Viking Technology’s ArxCis-NV™, has been architected to take advantage of the “best attributes” of the DRAM & NAND memory technologies. Together with advanced data movement logic and supercapacitor technology, the ArxCis-NV™ (a DDR3 NVDIMM / DDR4 NVDIMM)delivers exactly what the Enterprise market has been yearning for: A persistent, non-volatile DIMM that can be integrated into the main memory of industry standard server hardware.

HDD Drive Bays

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	HDD/SSD Drive Bays Drive bays house standard HDDs or SSDs, typically in 2.5” or 3.5” form factors. When using SSDs for application performance, users will employ the use of caching or tiering software; this software will use the DRAM for “write data activity”, meaning that the DRAM needs to be trusted / persistent or Non-Volatile.

Dram

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	DRAM DDR3 DIMMs. Servers can be populated with both standard (volatile) DIMMs along with ArxCis-NV (Non-Volatile DIMMs). Depending on the host application requirements, ArxCis can be populated in 1 or more of the available channels. In an Intel Sandy Bridge based server, there are 4 channels: a common integration path would be to populate 1 of the channels with ArxCis-NV, leaving the remaining 3 channels for standard (volatile) DIMMs.

Arxcis-nv

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	ArxCis-NV ArxCis-NV is the industry’s most advanced non-volatile DDR3 DIMM. Capable of retaining mission critical data in an event of a power-failure; the ArxCis-NV delivers the highest performance data security for many enterprise compute and storage applications.

Super Capacitors

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	Super capacitors Supercapacitors are used as the back-up power source for the ArxCis-NV DIMM in the event of a host system power-failure. The supercapacitors provide sufficient power to the ArxCis-NV DIMM, so that the SAVE & RESTORE functions of the NV-DIMM can be performed while mains power is unavailable.

Power supply

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	Power Supply When the AC/DC power fails, there is an early warning signal from the power supply to the system’s CPU. This signal initiates the sequence of events in which the ArxCis-NV performs a SAVE to the DRAM and CPU cache/buffer.

Non-Volatile deployed serverClick on highlighted areas for detailed description