Hi all,

I've spent a lot of time working with the SD/MMC card SPI protocol, and before I spend any more, I'd like a straight answer on this:

Has anyone been able to achieve throughput on the order of 800kiB/s to an SD/MMC card of any type over SPI?

My requirement is to send 1kiB blocks from an ADC as I acquire data, and I need to know if these speeds are even possible. I'm open to any tricks you're willing to share, including skipping the file system entirely. The cards I'm using are the high-speed variety, the kind that say "20MB/s" on them, but I have a sneaking suspicion that those advertised speeds are using the SD protocol with all sorts of asterisks attached.

--
Joel J. K. Parker
Systems Engineer
Radiance Technologies, Inc.
(256) 655-2463


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