Why adopt NVMe instead of older interfaces?
Older storage connection interfaces such as serial attached SCSI (SAS) and Serial Advanced Technology Attachment (SATA) cause bottlenecks in today's networks because they were designed for use with much slower HDDs and tape-based memory.
NVMe is designed to take advantage of solid state drive (SSD) memory's greater speed and better support for parallelism.
How does NVMe work?
NVMe achieves its speed in several ways:
- NVMe can perform parallel input/output (I/O) operations with multicore processors to facilitate high throughput.
- While Advanced Host Controller Interface (AHCI), the previous PCIe interface for SSD, must communicate with the SAS/SATA controller, NVMe communicates directly with the host CPU.
- NVMe has more command queues (64,000 vs. 1) and can send more commands per queue (64,000 vs. 32) than AHCI.
- In contrast to AHCI, NVMe utilizes low CPU cycles.
- NVMe operations have a latency of 2.8 microseconds versus AHCI's 6 microseconds.
- NVMe can perform over 1 million I/O operations per second (IOPS).
- NVMe supports SSDs with a variety of types of non-volatile memory (NVM), including NAND flash and 3D XPoint technology, which was developed by Intel and Micron to bring the performance characteristics of DRAM to NVM.
When should businesses use NVMe drives?
NVMe-based PCIe SSDs are more expensive than SATA and SAS options and may use more power. It's important to decide if the business's needs warrant the extra cost. Unless applications are data-heavy, or perform in settings where every microsecond counts, the business may not benefit from the expense.
The SCSI Trade Association claims that the most recent SATA-based SSD interfaces have some advantages over NVMe: easier scalability and reliable failover protections.
Another key point: NVMe is compatible only with SSD. If the business has larger capacity drives only available as HDDs still in use, or wants to be able to add them easily in the future, it will still have to use SATA or SAS, which are compatible with any type of media.
NVMe is not intended to make the older interfaces obsolete. Going forward, NVMe, SATA, and even SAS will make up a suite of options to choose from based on cost, processing needs, and power consumption.
How do businesses get started with NVMe?
NVMe compatibility is built into almost all server and workstation products. The decision is whether to purchase NVMe-compatible SSD memory, which comes in a variety of form factors for installation into servers and other hardware, including the familiar M.2 as well as some new NVMe-only sizes.
NVMe technology has found its way into consumer-grade products as well in the form of external hard drives and plug-and-play memory for CPUs. Through wider adoption and economies of scale, NVMe is expected to eventually become the most cost-effective option for memory.
