stimmer,
I understand the problem is with the library. I want to use the standard SPI library since it's a pain to maintain my own SPI layer for every chip that runs SdFat. Also, my SPI functions may not play well with the standard SPI library.
I would like to see optimized functions in the SPI library for sending and receiving blocks of data.
Pico,
I don't have a Maple version of SdFat with the new caching improvements for large memory chips. Others have ported old versions of SdFat to Maple but these are slow.