Editing PCI Express (section)

=== Storage devices ===
[[File:PCIe card full height.jpg|thumb|An [[OCZ]] RevoDrive [[Solid-state drive|SSD]], a full-height x4 PCI Express card]]
{{See also|SATA Express|NVMe}}

The PCI Express protocol can be used as data interface to [[flash memory]] devices, such as [[memory card]]s and [[solid-state drive]]s (SSDs).

The [[XQD card]] is a memory card format utilizing PCI Express, developed by the CompactFlash Association, with transfer rates of up to 1&nbsp;GB/s.<ref name="49Gx4" />

Many high-performance, enterprise-class SSDs are designed as PCI Express [[RAID controller]] cards.{{Citation needed|date=September 2021}} Before NVMe was standardized, many of these cards utilized proprietary interfaces and custom drivers to communicate with the operating system; they had much higher transfer rates (over 1&nbsp;GB/s) and IOPS (over one million I/O operations per second) when compared to Serial ATA or [[Serial attached SCSI|SAS]] drives.{{Quantify |reason=Listing numbers isn't a comparison.|date=September 2021}}<ref name="P3Feb" /><ref name="NeWKh" /> For example, in 2011 OCZ and Marvell co-developed a native PCI Express solid-state drive controller for a PCI Express 3.0 x16 slot with maximum capacity of 12&nbsp;TB and a performance of to 7.2&nbsp;GB/s sequential transfers and up to 2.52&nbsp;million IOPS in random transfers.<ref name="VLf63" />{{Relevance inline|reason=Can't find any info on whether this product was even sold, and I can't imagine it was when the other thing OCZ was in the news for at the time were their PCIe based SSDs being constantly failing nightmares that were impossible to recover because of the proprietary interface and required drivers... Enterprise would have rightfully scoffed at those numbers, thrown a couple thousand more regular SSDs in their giant storage arrays if they needed more than the billions of IOPS they were already achieving, maybe updated from 40&nbsp;Gbps to 100&nbsp;Gbps runs between the storage servers, and called it a day.|date=September 2021}}

[[SATA Express]] was an interface for connecting SSDs through SATA-compatible ports, optionally providing multiple PCI Express lanes as a pure PCI Express connection to the attached storage device.<ref name="ymSig" /> [[M.2]] is a specification for internally mounted computer [[expansion card]]s and associated connectors, which also uses multiple PCI Express lanes.<ref name="SNLQe" />

PCI Express storage devices can implement both [[AHCI]] logical interface for backward compatibility, and [[NVM Express]] logical interface for much faster I/O operations provided by utilizing internal parallelism offered by such devices. Enterprise-class SSDs can also implement [[SCSI over PCI Express]].<ref name="FJvMX" />