Differences between a MultiMediaCard (MMC) and a SecureDigital Card (SD Card)

There are so many memory cards in the market that, an amateur buyer always finds it difficult to buy the best card suitable for him or her. Two of the most popular memory cards are MultiMediaCard (MMC) and SecureDigital Card (SD Card). While MMC format was developed jointly by SanDisk and Siemens in 1997, SD card is the improved version of the original MMC format developed jointly by SanDisk, Panasonic and Toshiba. Both cards are solid and can withstand extreme temperature. But the SD card has some advantages over the MMC.

Physical distinction:  Both MMC and SD memory cards measure approximately 24mm x 32mm x 2.1mm and weights 2 grams. But the SD cards are slightly thicker than the MMC cards. Due to this additional thickness it enjoys advantages over MMC cards:

*Contacts of a SD cards are recessed beneath the surface of the card and this feature protects the contacts from contact with the fingers

* The SD can make contacts easily whereas an MMC card will go in most of the way but not make contact if inverted.

The SD cards also have a small tab on the left edge of the notch that allows users to manually write protect the data on the cards, but MMC cards do not have it.

Transfer rate: Although both of these cards have almost similar transfer rates, the rate would vary from device to device, application to application. Usually, normal cards transfer around 9-10MB/s. But ultra sophisticated cards with higher transfer rates are also available for professional users like photographers who need high speed transfer while shooting vider and also taking still photo in quick succession.

Capacity: Although SD Cards are often ahead over MMC in storage capacity, but MMC has almost caught up in the recent past.

Applications: Whatever the size of a card, either MMC or SDC, the card readers and connectivity ports like Universal Serial Port (USB) have made it possible to use any type of card in any slot interchangeably. Some cards are made with built in USB slots so it does not matter which card, all types can be used in any device.

Security: Due to the write protection feature of SD cards, they are more secured than MMC cards. The write-protection allows a user to manually lock the card and allow him to protect his data on the card from any accidental incident. SD card also offer copy rights protection as only licensed data can be written on it.