Definition: SD Express

An SD card category that uses the PCI Express (PCIe) and NVMe interfaces. Introduced in 2018, SDHD, SDXC and SDUC cards are available as SD Express cards, which are backward compatible with the myriad SD devices in use.

Over the PCIe bus, an SD Express card plugged into an SD Express host can reach up to 985 MB/sec, a 50% increase over the UHS-III bus in full-duplex mode. See SD card classes, SD card, PCI Express and NVMe.

microSD Express
Full-size SD Express cards did not take the world by storm, but the microSD version, which debuted in 2019, is expected to make a splash. Offering the same speed increase as SD Express, the microSD format is very popular and used in many devices. See microSD.

SD Express Logos

As time marches on, more Express logos will appear on cards. (Images courtesy of SD Association, www.sdcard.org)