HOWTO: Compare the merits of MMC Vs SD Memory cards

MMC - MultimediaCard and SD - SecureDigital are two alternative memory card standards.

Whilst they are closely related, they are distinct standards in their own right and managed by separate corporations and associations.

• MMC cards are compatible with both MMC slot devices AND SD slot devices. (e.g. Nokia, Siemens, Samsung, Sharp, Motorola phones and SD slot cameras))
  

• SD cards are only compatible with SD slot devices. (which excludes Nokia and Siemens phones and other MMC devices)

This makes a like-for-like comparison between MMC and SD fairly straightforward, as one standard has a much wider range of devices with which it is compatible.

However, it is not quite that simple because SD cards do have some additional functions in the hardware specification, including a write-lock toggle, and some wiring for enabling digital rights management on the card.

In the vast majority of cases, i would say the broader compatibility across both SD and MMC is the more useful feature to have, especially as digital rights management is a feature of most use to owners of copyrighted material who want to protect it.

hope this helps