CFexpress vs. MultiMediaCard (MMC)
Comparing 2 standards across 14 specifications. 14 key differences identified.
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.
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.
Specification Comparison Table
14 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Body
|
CompactFlash Association (CFA) | — |
|
Underlying Storage Architecture
|
PCI Express (PCIe Gen 3 / Gen 4 / Gen 5) + NVM Express (NVMe v1.3/1.4) | — |
|
Type A Dimensions & Bus
|
20.0 × 28.0 × 2.8 mm | 1-lane PCIe (1 GB/s PCIe 3.0 / 2 GB/s PCIe 4.0) | — |
|
Type B Dimensions & Bus
|
38.5 × 29.6 × 3.8 mm | 2-lane PCIe (2 GB/s PCIe 3.0 / 4 GB/s PCIe 4.0) | — |
|
Type C Dimensions & Bus
|
54.0 × 72.0 × 4.4 mm | 4-lane PCIe (4 GB/s PCIe 3.0 / 8 GB/s PCIe 4.0) | — |
|
Type B XQD Compatibility
|
Physically identical exterior shell to Sony XQD (host backward-compatible via firmware) | — |
|
Operating Power Tiers
|
Up to 1.7W (Type A) / Up to 3.0W (Type B) / Up to 6.0W (Type C) | — |
|
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) |
|
Operating Voltages
|
— | 3.3V (standard) / 1.8V (dual voltage / eMMC) |