lass_sd_fat.html" title="Main file system class for SdFat library. ">SdFat</a> has a single 512 byte buffer for I/O so it must write the current data block to the SD, read the directory block from the SD, update the directory entry, write the directory block to the SD and read the data block back into the buffer.</p>
<p>The SD flash memory controller is not designed for this many rewrites so performance may be reduced by more than a factor of 100.</p>
<p>If ENDL_CALLS_FLUSH is zero, you must call flush and/