Gp2x Sd Card Writing Speed

[nubie]

MMC is not neccessarily slower.

I have an A-Data "MMC 4.0" 1GB 100x card and it works very fast. I am able to watch the 720x500 whatever mp4s right off of it just fine. and it only takes a couple seconds to move 50 or so megabytes onto it.

the carton says 15MB/s read, 8MB/s write. sounds fine by me, I have never seen a move encoded above 2MB/s anyway.

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If you look at the SD specifications, it says that MMC is usually a 1-wire data transfer, running at speeds of upto 400Khz. SD is usually a 4-wire data transfer running at speeds of upto 25Mhz (but is backwards compatible, so can also be run as a 1-wire, 400Khz card).

So, to get 15MB/sec, you must be using 4 parallel data lines, and thus the card must be a SD card, not a MMC card.

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It is an mmc card, the package says "MMC4.0 MMCplus" on the front.

the back says "MMC4.0 standard, supports 1bit/4bit/8bit data transfer."

It has no SD latch on the side for write protect, and the card itself says MMC plus card 100x

I am not sure if this is new, but it is really what I have. I also notice 4 extra contacts on the underside and 2 of the regular SD contacts are double length.

Edit: Wikipedia MMC I looked here and found this:

MMC originally used a 1-bit serial interface, but newer versions of the specification allow transfers of 4 or sometimes even 8 bits at a time.

And this:

Standard 4.x (4.0, 4.1, etc) was released in 2005 (MMCA System Specification 4.1). This new standard involves the higher performance MMC4 (with the same basic MMC form factor but more pins) called called MMCplus, . . .

Edit: cut out some of the last pasted paragraph