Embedded MultiMediaCard or eMMC is an internal flash storage based on the MultiMediaCard or MMC standard. Note that MMC is the precursor to Secure Digital or SD card. First introduced by SanDisk and Siemens AG in 1997, it was once a popular external storage medium used for digital cameras, desktop and laptop computers, digital media players and portable music players, personal digital assistants or PDAs, and mobile devices.
The popularity of MMC dwindled with the arrival of newer storage mediums such as SD cards and microSD cards. However, the introduction of eMMC demonstrated an attempt to repurpose the MMC technology as an internal storage medium.
An Embedded MultiMediaCard is fundamentally a Ball Grid Array package of MMC consisting of three components: the MMC interface, the flash memory, and the flash memory controller. These components are contained within a single circuitry module. The entire module is usually soldered or attached to the motherboard of a particular device to serve as an internal storage system based on solid-state NAND flash memory.
eMMC soon became a popular internal storage option for several portable devices such as smartphones and laptops due to its inherent advantages that center on practicality and feasibility. Of course, because it remains an inferior technology based on the standards of today, it has notable drawbacks and limitations.
Pros of Embedded MultiMediaCard: Advantages of eMMC
Considerable High Storage Capacity
One of the key advantages of eMMC is that it has a high storage capacity considering its size. The capacities range from 1GB to 512GB. These options make them ideal for a wide range of internal storage applications to include smartphones, tablets and laptops based on Windows, Chrome OS, and Linux distributions such as Debian and Ubuntu, and smart devices, as well as for industrial applications to include the Internet of Things.
Small Size Means Small Footprint
The physical dimension of an Embedded MultiMediaCard is between 11 x 10 x 0.8 mm to 11.5 x 13 x 1.2 mm. Take note that a solid-state drive based on PCIe is 10 times to 20 times larger than an eMMC. An internal storage solution with a high storage capacity is undeniably ideal for portable devices. Its small footprint, coupled with its high storage capacity, make it an ideal internal storage solution for slim laptops and netbooks, as well as smart devices.
Inexpensive Internal Storage Solution
Most manufacturers of inexpensive laptops and devices such as smartphones and tablets prefer using an Embedded MultiMediaCard because it is inexpensive compared to other smaller internal storage solutions such as Universal Flash Storage or UFS and NVMe-based solid-state storage. The cost reduction gained from using this storage technology allows manufacturers to lower their production costs and sell their products at lower price points.
Relatively Consumes Less Power
Energy efficiency is another advantage of eMMC. Version 5.1 can run between 1.95 volts to 3.6 volts and consumes between 4 to 7 watts depending on load. These characteristics make it an ideal option for low-powered laptops and power-efficient smaller smart devices with smaller battery capacities. As a comparison, note that an M.2 solid-state drive consumes between 5 to 8 watts depending on the load and runs.
Read and Write Performance Speed
Another advantage is operational or performance efficiency. Version 5.1 of an Embedded MultiMediaCard has a read speed of 250 MB/s and a write speed of 125 MB/s. A microSD card has around 90 MB/s read speed and 40 MB/s write speed, while a SATA III hard disk drive has a read speed of around 109 MB/s and a write speed of 108 MB/s.
Cons of Embedded MultiMediaCard: Disadvantages of eMMC
Slower Compared to Other Technologies
A major disadvantage of eMMC is that it is not the fastest internal storage technology. A 512 MB UFS has a sequential read speed of up to 2100 MB/s and a sequential write speed of 410 MB/s, while an SSD based on PCIe NVMe protocol can reach a read speed of 3500 MB/s. Note that most Android devices begin using UFS beginning in 2016, while Apple first introduced an NVMe storage implementation on the iPhone 6S in the same year.
Outdated Architecture of eMMC
One of the reasons why an eMMC is slower when compared to other storage technologies is its outdated architecture. For starters, it usually operates with fewer memory gates than solid-state drives. It also uses a single lane each way while an SSD uses a multi-lane highway. What this means that although it can theoretically rival the data transfer speeds of a SATA-based SSD, it cannot transfer at the same volume. More lanes mean moving more data at a time, while a single lane that allows only one direction at a time moves fewer data.
Note Readily Upgradable Internal Storage
Another drawback of an Embedded MultiMediaCard is that it is not upgradeable. Laptops that come with this internal storage cannot be upgraded easily. Unlike M.2 SSDs that can be detached and swapped with ease, an eMMC is soldered on the motherboard. Of course, it can be removed and replaced using a heat gun and a soldering tool but doing so requires technical skills to avoid damaging the mainboard. Exposure to excessive heat can damage hardware components.