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NVM Express, NVMe, or Non-Volatile Memory Host Controller Interface Specification (NVMHCI), is a specification for accessing solid-state drives (SSDs) attached through the PCI Express (PCIe) bus. "NVM" stands as an initialism for non-volatile memory, which is used in SSDs. As a logical device interface, NVM Express has been designed from the ground up, capitalizing on the low latency and parallelism of PCI Express SSDs, and mirroring the parallelism of contemporary CPUs, platforms and applications. By allowing parallelism levels offered by SSDs to be fully utilized by host's hardware and software, NVM Express brings various performance improvements. NVM Express SSDs exist both in form of standard-sized PCI Express expansion cards and as 2.5-inch drives that provide a four-lane PCI Express interface through the U.2 connector (formerly known as SFF-8639). SATA Express storage devices and the M.2 specification for internally mounted computer expansion cards also support NVM Express as the logical device interface.〔 == Background == Historically, most SSDs used buses such as SATA, SAS or Fibre Channel for interfacing with the rest of a computer system. Since SSDs became available in mass markets, SATA has become the most typical way for connecting SSDs in personal computers; however, SATA was designed primarily for interfacing with mechanical hard disk drives (HDDs), and has become increasingly inadequate as SSDs had improved. For example, unlike hard disk drives, some SSDs are limited by the maximum throughput of SATA. High-end SSDs had been made using the PCI Express bus before NVMe, but using non-standard specification interfaces. By standardizing the interface of SSDs, operating systems only need one driver to work with all SSDs adhering to the specification. It also means that each SSD manufacturer does not have to use additional resources to design specific interface drivers. This is similar to how USB mass storage devices are built to follow the USB mass-storage device class specification and work with all computers, with no per-device drivers needed.〔 〕 , a new standard for using NVMe over Fibre Channel is also in development. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NVM Express」の詳細全文を読む スポンサード リンク
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