Embedded MMC
The embedded MultiMediaCard (eMMC, officially branded as e•MMC) is a type of internal storage that integrates NAND flash memory,[15] a buffer, and a controller into a single ball grid array (BGA) package. Unlike other forms of removable card-based MMC storage, eMMC is permanently soldered onto a device's printed circuit board (PCB) and is not user-removable or upgradeable. The onboard controller manages tasks such as error correction and data handling, reducing the workload on the device's main processor. eMMC chips use an 8-bit parallel interface and are available in various physical sizes and storage capacities.[16][17]
The eMMC standard was first introduced by the JEDEC Solid State Technology Association in 2006 with version 4.0, which adapted the original card-based MMC specification for embedded (non-removable) and mobile applications.[18] Between 2007 and 2012, the version 4 standard was revised multiple times to improve performance and introduce features such as secure erase and on-system firmware updates. Version 5.0, released in 2013, introduced the HS400 interface mode, enabling theoretical data transfer speeds of up to 400 MB/s, along with enhancements to reliability and boot performance. This was followed by version 5.1 in 2015, which added command queuing and further reliability improvements.[19] The most recent update, version 5.1A, was released in 2019 and included minor refinements to the standard.[20]
eMMC became widely used as the primary storage medium in early smartphones, and later in low-cost laptop computers, Chromebooks, tablet computers, and other compact computing devices. While it was gradually supplanted in higher-performance devices by alternatives such as Universal Flash Storage (UFS) in smartphones and solid-state drives (SSDs) in computers, eMMC continued to be used in entry-level products due to its low cost,[21] compact form factor, low power consumption, and adequate performance for everyday tasks such as web browsing, email, and video streaming.[19]
While eMMC is faster and more power-efficient than traditional hard disk drives, it is slower than most SSDs, especially those using NVMe over PCI Express. These speed limitations make it less suited for applications involving large files or intensive computing needs, such as gaming or video editing. Its lack of upgradeability also limits its appeal in more advanced systems, as users cannot replace or expand storage after purchase.[19]
Higher capacity variants of eMMC reach higher writing speeds. While the reading speed of eMMC 5.0 remains constant at 250 MB/s throughout its storage options, a 64 GB eMMC 5.0 writes at up to 90 MB/s, more than six times faster than the 14 MB/s of the lowest storage option of 4 GB.[25]
