[5][6] As a widely adopted computer bus, PCI Express provides sufficient bandwidth while allowing easy scaling up by using faster or additional lanes.

While the support for AHCI ensures software-level backward compatibility with legacy SATA devices and legacy operating systems, NVM Express is designed to fully utilize high-speed PCI Express storage devices by leveraging their capability of executing many I/O operations in parallel.

[11][12] While evaluating different approaches to the required speed increase, designers of the SATA interface concluded that extending the SATA interface so it doubles its native speed to 12 Gbit/s would require more than two years, making that approach unsuitable for catching up with advancements in SSD technology.

[6][13] Some vendors also use proprietary logical interfaces for their flash-based storage products, connected through the PCI Express bus.

[17][18] In December 2013, Asus unveiled a prototype "Z87-Deluxe/SATA Express" motherboard based on the Intel Z87 chipset, supporting Haswell processors and using additional ASMedia controller to provide SATA Express connectivity; this motherboard was also showcased at CES 2014 although no launch date was announced.

SRIS eliminates the need for complex and costly shielding on SATA Express cables required for transmitting PCI Express synchronization signals, by providing a separate clock generator on the storage device with additional support from the motherboard firmware.

[21][22][23] In May 2014, Intel Z97 and H97 chipsets became available, bringing support for both SATA Express and M.2, which is a specification for flash-based storage devices in form of internally mounted computer expansion cards.

In more detail, using two PCI Express 2.0 lanes provides a total bandwidth of 1000 MB/s (2 × 5 GT/s raw data rate and 8b/10b encoding), while using two PCI Express 3.0 lanes provides 1969 MB/s (2 × 8 GT/s raw data rate and 128b/130b encoding).

That choice allowed easier backward compatibility with legacy SATA devices, together with making it possible to use cheaper unshielded cables.

As of March 2015[update], some NVM Express devices in form of 2.5-inch drives use the U.2 connector (originally known as SFF-8639, with the renaming taking place in June 2015[33]),[35][36] which is expected to gain broader acceptance.