NVMe (NVM Express) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is a host controller interface and storage protocol that increases the rate of transfer of data between enterprise and client systems as well as solid-state drives (SSDs), and this is over a Peripheral Component Interconnect Express (PCIe) bus.
NVMe gives you an alternative to the Small Computer Systems Interface (SCSI) standard and the Advanced Technology Attachment (ATA) standard. These standards were developed and were in use during a period when hard disk drives (HDDs) were the primary storage media. NVMe was designed to be used for media that is much faster.
This system has faster data transfer rates, reduced latency, and higher input/output operations per second and much lower power consumption.
How does NVMe work?
The I/O commands and responses to a shared memory in a host computer over a PCIe interface is mapped by NVMe. This interface supports parallel I/O with multicore processors and this facilitates high throughput and reduces bottlenecks in the central processing unit.
It also has a more streamlined command for processing I/O request than what SCSI and ATA command sets. NYMe also needs only less than half the amount of CPU instructions than the SCSI command set does with SAS devices and ATA does with SATA drives.
NVMe is capable of handling 64,000 commands in a single message queue as opposed to SATA devices that handle 256 commands and a SATA drive that handles 32 commands.
History of NVM Express
The first version of the NVM Express was published March 2011. This 1,0 specification had the queuing interface, NVM command set, administration command set and the security features included in them.
An updated version was released on Oct. 11, 2012. NVMe 1.1 had support for SSDs with multiple PCIe ports and this had support for SSDs with multiple PCIe ports which were there to enable multipath I/O and namespace sharing. New capabilities included autonomous power state transitions during idle time and also reservations that were included which allowed two or more hosts to coordinate the access to a shared namespace. This was done to improve fault tolerance.
NVMe Express Inc.
The NVM Express Work Group became the NVM Express Organization in March 2014. The founding members included Cisco Systems, Dell, EMC, Western Digital’s HGST subsidiary, Intel, LSI, Micron technology, NetApp, Oracle, PMC-Sierra, Samsung Electronics, SanDisk.
This non-profit organization went through some changes and became known as NVM Express Inc. It has more than 100 technology companies as its members.
It also has a 13 member board of directors that govern and guide the company’s strategic direction. Out of the 13, six members serve multiyear terms and seven who are elected on an annual basis from the NVMe Express membership. The members with multiyear terms that expire in 2017 are Cisco, Dell EMC, Intel, Microsemi, NetApp, and Oracle. Members who were elected in 2017 for single-year terms are Facebook, Micron, Microsoft, Samsung, Seagate, Toshiba, and Western Digital.