Typically, an MMC is used as storage media for a xbox 360 sd card slot device, in a form that can easily be removed for access by a PC. MMC and SD cards differ in their physical size, capacity and their usage. Both come in different memory sizes as well.
While MMCs can be used in a standard SD card slot, the latter cannot be used in a MMC slot. It is a flash memory card format. 4 mm, RS-MMC – 24 mm x 18 mm x 1.
Originally it used a 1-bit serial interface, but with the new architecture, now it can transfer 4 or 8 bits at a time. After the release of MMC cards most of the portable music players started using MMC cards as primary storage. But the music industry was skeptical about the use of MMC, as MMCs would allow easy piracy of music. So, Toshiba added encryption hardware in existing MMC and named it Secured Digital or SD card.
Today, in many areas, MMC are being replaced by SD cards. The only reason why some devices continue using MMCs are because of their comparative lower cost than SD cards. The size of a standard MMC card is 24 mm x 32 mm x 1.
So from the size comparison, we can see that SD cards are much thicker than the MMC cards, 2. Because of the size similarity, MMC cards can be also used in the standard SD card slot, but the reverse is not true. MMCs are currently available in sizes up to 4 GB and 8 GB models. As of September 2007, SD cards were available in sizes from 8 MB to 16 GB.
A few companies have announced SD cards with 32 GB also. Amongst digital cameras, companies that use SD cards include Canon, Epson, Casio, HP while Epson and some models of Nikon and Sony cameras use a MMC card and compact flash memory depending on the model.
In Mobile phones, Nokia uses both MMCs and SD cards which vary according to the model. Samsung and Motorola phones use SD cards. Amongst gaming consoles, Nintendo Wii and Sony Playstation 3 use SD cards while Xbox 360 uses a memory unit.