NEXT-GENERATION SOLID STATE DRIVES
When Intel launched the Z97 chipset, motherboards started to feature a new type of connector called M.2. Its main use so far has been for SSDs, with one of the main advantages being its ability to carry data across either the SATA or PCI-E bus, with the latter offering the potential for much faster transfer speeds than you get from a standard 2.5in SATA SSD.
M.2 storage devices are much smaller, squeezing the NAND flash, controller and memory cache onto a stick that measures 22mm wide and (usually) 80mm long. The connector delivers both power and data, and needs no extra cabling, enabling you to fit a whole PC into even smaller cases, or entirely remove the drive caging from your chassis, giving you extra room for water-cooling kit, or whatever takes your fancy.
There’s more to M.2 though. Along with this new form factor, a new bus protocol called NVMe has been designed to replace AHCI, a standard introduced over ten years ago for connecting storage devices to a PC. It supports much longer command queues, and reduces overheads for superior transfer speeds and lower latency. At this early stage, M.2 complements rather than replaces traditional SATA ports, but it also co-exists with PCI-E add-in cards, which can offer the same faster speeds.
These new standards, connectors and device sizes have made PC storage more interesting, but also a little confusing. As such, over the next few pages, we’ll not only review several M.2 and PCI-E SSDs, but also explain how M.2 works and the differences between drives.