NVM express was developed from 2008 to 2011 to replace Serial Advanced Technology Attachment (SATA) and Serial Attached SCSI (SAS) protocols. NVMe’s improvements in latency and performance over its competitors contributed to the development of other important technologies, including the Internet of Things (IoT), artificial intelligence (AI) and machine learning (ML). 

Today, users demand faster response times than ever from their applications. The NVMe protocol was built to deliver a next-generation, high-performance, high-bandwidth and low-latency experience, regardless of the type of application a user is deploying. NVMe SSDs access flash storage primarily through a Peripheral Component Interconnect Express (PCIe) bus that removes the “middle man” controller, reducing latency. However, NVMes can also run on any type of “fabric” interconnect—such as Fibre Channel and Ethernet—and within Ethernet, iWarp, RoCEv2, iSER and NVMe-TCP.

NVMe SSDs can run tens of thousands of parallel command queues and run programs at faster speeds than drives connected by using SCSI protocol, which can only deploy a single command queue. The connection method is independent of the protocol; for example, NVMe PCIe can connect a single drive via a PCIe link running the NVMe protocol.

NVMe was built for high-performance, non-volatile storage media, making it ideal for today’s demanding, compute-intensive environments like graphics editing software, cloud computing environments, firmware and large databases. NVMe deals with enterprise workloads swiftly and efficiently with a smaller infrastructure footprint and less power than SCSI.

While HDDs were the industry-preferred method of storing and accessing data, SATA and SAS were appropriate solutions. Both technologies were designed as SCSI storage interfaces to facilitate the transfer of data to and from HDDs. SAS connects a single drive via a SAS port running the SCSI protocol that then connects to a PCIe link. SATA connects a single drive via a SATA port running the ATA protocol via an ATA controller that then connects to a PCIe link. 

Until recently, most SSDs used SAS or SATA to connect with the rest of a computer system. However, with the rise in solid-state technology across the storage industry, SAS and SATA became more of an awkward fit, as they had been used with HDDs. According to a 2023 International Data Corporation (IDC) report, NVMe was designed to speed data transfer to systems connected via a PCI express, a serial expansion bus that’s standard for connecting a computer to one or more peripheral devices.¹

In addition to the fact that it was designed specifically for use with SSDs, NVMe’s protocol is more streamlined than SCSI, making it a better solution for real-time applications, such as ML and AI. With the increasing popularity of cloud computing environments, NVMe is also well positioned to support hybrid cloud, multicloud and mainframe storage environments because of its built-in high performance and data protection. 

Here are some of the benefits of using NVMe storage over SAS or SATA drives:

Better performance: NVMe technology can use a PCIe to connect SSD storage directly to a server or central processing unit (CPU). This marked improvement in performance has made NVMe technology the preferred data storage/transfer option for gamers, video editors and other users that require higher performance than SAS or SATA HDDs can offer.

Higher speed: NVMe drives can deliver higher speeds than SAS or SATA drives because they can send and receive NVMe commands faster and deliver better throughput.

Increased compatibility: NVMe is widely considered a more compatible option than SAS/SATA and is frequently updated as it develops alongside such critical, fast-moving technologies as AI, ML and cloud computing. NVMe technology can work seamlessly with all modern operating systems, including mobile phones, laptops and gaming consoles.

Improved bandwidth: The PCIe connection is wider and has more bandwidth than SAS or SATA ports. It also improves with each generation, doubling the bandwidth of the previous generation. SAS and SATA have lower bandwidth connections and are fixed, so they don’t improve over time. Another feature that makes PCIe connections stand apart is that they are scalable in "lanes," so even in the same generation, users can double the bandwidth with twice the number of lanes. 

For a deep dive into NVMe and SATA, check out "NVMe versus SATA: What's the difference?

Until the advent of SSDs and flash storage, SATA was used with all HDD storage systems. However, as mobile applications, video games and new technologies like AI increased the demands on computing environments, SATA’s limitations became apparent. Specifically, SATA’s low speed and bandwidth began to slow down large data transfers that were key to the functions of new applications.

NVMe was invented as a better data storage/transfer option than SATA for SSDs in environments where large data transfers were needed without slowing down processing times. NVMe enables SSDs to connect directly to the CPU by using the PCIe bus and an M.2 or U.2 adapter—the same as with a SATA drive. NVMe allows SSDs to connect right into the CPU and read and write large volumes of data swiftly.  

To achieve higher performance, NVMe defines a register interface, command set and group of features for PCIe-based SSDs. Once connected through the PCIe bus, the NVMe protocol facilitates lower latency and helps optimize I/O operations per second (IOPS).

NVMe drivers support many kinds of operating systems (OS), including Windows, Linux and MacOS. Also, NVMe protocol supports all kinds of NVM, including NAND flash-enabled SSDs. Finally, NVMeuses parallel command queues and a “polling loop” rather than its predecessors’ “interrupt” based device driver, reducing latency and system overheads and helping avoid CPU bottlenecks—such as when a graphics card works faster than the underlying CPU.   

NVMe SSD form factors

Another important differentiator of NVMe specifications is its form factor, or the way size, configuration and physical design impact its compatibility with other devices. Recently, the Storage Networking Industry Association (SNIA) convened to establish the Enterprise and Datacenter Standard Form Factor (EDSFF) to create an agreed upon, industry-wide framework for SSD technology.

The agreed upon, standard form factor for an SSD was 2.5 inches, which easily fits into the drive bay of most laptops and desktops, making NVMe SSDs highly compatible with existing technology. Since the 2.5-inch drive is widely used in both consumer and commercial computing environments, replacing an HDD with an NVMeSDD is simple and straightforward for users wanting to upgrade their system’s performance.

m.2 NVMe drives

M.2 SSDs are another physical form factor or connector used in SSDs. While the term is often used interchangeably with NVMe, they are different kinds of storage technology. While NVMe SSDs attach to a PCIeslot on a motherboard, giving them much higher data transfer rates than their competitors, m.2 drives are a physical form factor, or connector, that enable high-performance storage in small, power-constrained devices such as ultra-thin laptops and tablets.

NVMe and dynamic random-access memory

Dynamic random-access memory (DRAM) is a widely used type of random-access memory (RAM) that personal computers (PCs), servers and workstations rely on. NVMe SSDs come in both DRAM and DRAM-less varieties. NVMe SSDs with DRAM are more expensive and faster than DRAM-less ones, and they are a better option for graphic-intensive applications like photo or video editing software. DRAM-less NVMes are more affordable and slower, but still much faster than HDDs or SATA SSDs, making them good options for users who don’t need as much speed or performance for the applications they’re running.