Avoid slow flush command on ALFAT modules


We have a measurement device that needs to write about 4kb data to an SD card every second. I learned from this forum (and experienced myself) that the flush takes a lot of time, so I am wondering how I can optimize the usage. The idea is to avoid frequent calls while some data loss is acceptable. But how much data will be lost at all?

[ol]When I continuously write data without any flush will all the data be lost with a power failure or is there some internal operation that writes intermediate data back to the card from time to time?
When I continuously write data without any flush will the input buffer of the ALFAT module overflow some time?
Does a flush command with more data take significiant more time than a flush with less data in the buffer?[/ol]


@ ctk -

  1. Without flush, data can be lost.
  2. I remember we tried few MB without flush, it is just fine.
  3. Sure, but I don’t think it is too much different.