Memory Cards

CFast is a high-speed solid-state memory card standard developed by the CompactFlash Association (CFA) based on the Serial ATA (SATA) bus. Introduced with CFast 1.0 (SATA-II 3 Gbps) and refined in CFast 2.0 (SATA-III 6 Gbps), it delivers data throughput up to 550–600 MB/s in a rugged 24-pin form factor, widely adopted in professional cinema cameras (ARRI, Blackmagic, Canon).

CFexpress is an ultra-high-speed removable solid-state storage media standard developed by the CompactFlash Association (CFA). Built directly on the PCI Express (PCIe Gen 3/Gen 4) physical bus and NVM Express (NVMe) command set, it is the dominant storage medium for high-end professional digital cinema, mirrorless photography, and broadcast video.

CompactFlash (CF) is the pioneering solid-state removable memory card standard introduced by SanDisk in 1994 and maintained by the CompactFlash Association (CFA). Based on a 50-pin Parallel ATA (PATA / IDE) interface, it dominated professional DSLR photography and industrial computing for two decades, scaling through CF+ specifications up to UDMA 7 (167 MB/s).

microSD (originally developed as TransFlash / T-Flash by SanDisk in 2004 and ratified by the SD Association in 2005) is the ultra-compact form factor of the Secure Digital family. Measuring 15.0 × 11.0 × 1.0 mm (approximately 20% the size of a standard SD card), it is the universal removable storage medium for smartphones, action cameras, drones, and handheld gaming consoles.

MultiMediaCard (MMC) is a solid-state memory card standard introduced in 1997 by Siemens and SanDisk based on a 7-pin serial bus. Evolving into RS-MMC and MMCmobile, it formed the physical and protocol foundation of both the SD card and JEDEC eMMC (embedded MultiMediaCard), the ubiquitous internal storage standard for mobile devices, smart TVs, and single-board computers.

SD Bus Interfaces define the physical and electrical signaling architectures through which SD and microSD cards transfer data with host controllers. Spanning legacy Default/High Speed, Ultra High Speed tiers (UHS-I up to 104 MB/s, UHS-II up to 312 MB/s, UHS-III up to 624 MB/s), and PCIe/NVMe-based SD Express (up to 3,940 MB/s).

The SD Card (Secure Digital) is the global standard removable flash memory form factor established in 1999 by Panasonic, SanDisk, and Toshiba (SD Association). Measuring 32.0 × 24.0 × 2.1 mm, it spans capacity generations from original SDSC (up to 2GB) and SDHC (up to 32GB) to SDXC (up to 2TB) and SDUC (up to 128TB).

SD Speed Classes are standardized performance metrics defined by the SD Association to guarantee minimum sustained write speeds for uninterrupted video recording and random IOPS execution for applications. They encompass legacy Speed Class (C2–C10), UHS Speed Class (U1/U3), Video Speed Class (V6–V90), and Application Performance Class (A1/A2).

Memory Stick is a proprietary removable solid-state flash memory card format introduced by Sony in 1998. Evolving across standard, PRO (expanded capacity), Duo (compact form factor), PRO-HG Duo (60 MB/s high-speed), and Micro M2 variants, it featured Sony's MagicGate hardware DRM copy protection across Cyber-shot cameras, Handycam camcorders, VAIO laptops, and the PlayStation Portable (PSP).

xD-Picture Card ('eXtreme Digital') is a proprietary flash memory card format developed by Olympus and Fujifilm in 2002 (manufactured by Toshiba and Samsung). Measuring 20.0 × 25.0 × 1.7 mm with 18 surface pads, it utilized a controllerless architecture where the host camera directly managed the raw NAND flash silicon, before being discontinued in 2010 in favor of SDHC.