MultiMediaCard (MMC) vs. SD Card
Comparing 2 standards across 13 specifications. 13 key differences identified.
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.
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).
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
Operating Voltages
|
3.3V (standard) / 1.8V (dual voltage / eMMC) | 2.7V–3.6V (Standard) / 1.8V (UHS-I/II signal voltage) |
|
Governing Standards Bodies
|
MMCA (historically) / JEDEC (eMMC Standard JESD84-B51A) | — |
|
Introduction Year
|
1997 (Siemens & SanDisk) | — |
|
Physical Dimensions (Full MMC)
|
32.0 mm × 24.0 mm × 1.4 mm (7-pin interface) | — |
|
Reduced Size Formats
|
RS-MMC (24.0 × 18.0 × 1.4 mm), MMCmobile (dual voltage), MMCmicro (14.0 × 12.0 × 1.1 mm) | — |
|
Embedded Evolution
|
eMMC (eMMC 4.5, 5.0, 5.1 delivering up to 400 MB/s via 8-bit parallel bus in BGA packaging) | — |
|
Bus Widths
|
1-bit (legacy MMC), 4-bit (MMC Plus), 8-bit (eMMC HS400) | — |
|
Governing Body
|
— | SD Association (SDA) |
|
Physical Dimensions
|
— | 32.0 mm × 24.0 mm × 2.1 mm |
|
Pin Configurations
|
— | 9 pins (UHS-I / Legacy) / 17 pins (UHS-II / UHS-III dual-row) / 19 pins (SD Express) |
|
Capacity Standards
|
— | SDSC (≤2GB), SDHC (4–32GB), SDXC (64GB–2TB), SDUC (2TB–128TB) |
|
Standard File Systems
|
— | FAT12/16 (SDSC), FAT32 (SDHC), exFAT (SDXC / SDUC) |
|
Mechanical Features
|
— | Write-Protect slide notch (left edge), 45-degree polarized corner keying |