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Project - Speed test for SD cards


I just posted Speed test for SD cards on Codeshare. Feel free to discuss and make suggestions here.


Looks promising, its time for the great SD card shootout! :clap:


Well yes, that was my thought. But for me it turned out, that the difference between cards is not to large.

A big factor is the firmware. My G120 on the FEZ Cobra II took ~2min to write 4mb with the firmware from 2013 R2. With the 2014 R1 firmware that dropped to 1:20.

Thanks a lot to GHI here.


A table which compares SoM, FW and Card would be nice.
If the test environment is defined well anyone could contribute.


I did some tests today with all SD cards I could get hold of in my company.

I wrote 32 files with 64kb each = 4mb of data.

The picture shows the results for my G120 with 2014R1 firmware.

In short the card doesn’t really matter much, as long as it is not extremely old. To write 4 mb takes a bit more than 1 minute.


I got the G400 running with the SD card module. It is much faster than the G120, but a bit picky with the SD card. I get exceptions with 3 out of 5 cards.

Does anybody know a 16GB card that works reliably?



I ordered another bunch of SD cards. I took MicroSD cards with adapters.

The result was much better now. G400 could communicate with 6 out of 7 cards. There was also a considerable difference in speed.