Non-Volatile Memory Express

NVMe (Non-Volatile Memory Express) is a protocol for accessing SSD drives via the PCI Express bus. It is designed for high-speed data processing, which increases application performance. NVMe increases the speed of data storage systems (DSS) several times over compared to current standards. Today, it is mainly used in the enterprise market.

How it works

To work with the NVMe protocol, SSD drives are connected via the PCI Express bus, which allows up to four parallel lines to be used. The maximum data processing speed reaches 32 Gb/s, which is 5 times faster than SATA.

Information is read directly, which increases software performance and response time.

NetApp was the first vendor to adopt this technology. The company has long been a leader in the storage market and is usually the first to implement new developments in its solutions. The model range that uses NVMe technology includes all-flash solutions (e.g., AFF A250).

In 2020, Dell presented a completely new line of storage systems called PowerStore (e.g., 3000T). It only works on SSD drives with the NVMe protocol. The solution is scalable both horizontally and vertically.

Dell has implemented two storage system options. One with a traditional OS (with the letter T added at the end) and one with a hypervisor (letter X).

Huawei has also joined the fray and included support for the NVMe protocol in its Dorado models (e.g., Dorado 5000 V6). These storage systems also belong to the all-flash class and are supplied by the vendor for specific customer tasks.

Lenovo has been working with NetApp for several years, so the storage system model range is essentially OEM (Original Equipment Manufacturer). ONTAP is used as the operating system on data storage systems, and all the additional features of the American partner are also available, such as DM 5000F.

Fujitsu has integrated the NVMe protocol into its AF storage line.

To work with the NVMe protocol, it is not enough to implement support at the hardware level alone. Software development is also required. After the technology appeared, all vendors updated their software to the latest versions and included support for the protocol.

Form factors

Since NVMe is a standard, it is used on different SSD form factors.

1. PCI Express. Used on both server and desktop platforms. It was used as the only connection option when the technology first appeared.
2. M.2. Mainly intended for laptops and workstations. A compact form factor that supports a maximum SSD length of 110 mm. Accepted M.2 standards: 2230, 2242, 2260, 2280, 22110.
3. U.2. Similar to M.2, but used in server solutions. Compatible with server platforms in terms of mechanical parameters.
4. EDSFF. Developed by Intel mainly for its own solutions and SuperMicro platforms. It is an alternative to the U.2 form factor.
5. NGSFF. Another alternative to U.2, developed by Samsung. Works with self-assembled solutions on Intel, Supermicro, and other platforms. It is smaller in size compared to the previous form factor.

NVMe in SAN

The protocol is used not only in local servers, but also for building SAN data storage networks. The standard is called NVMe-over-Fabrics.

In block-level data transfer protocols (such as Fibre Channel), SCSI command support is replaced by NVMe. As a result, the latency does not exceed 10 ms.

The technology appeared in mid-2016 and is now actively developing in the Enterprise market.