# Advanced use `fastRead`

- All read commands take a last boolean argument `fastRead`. This argument defaults to `FALSE`, and does not need to be specified when calling a function.

For example:

    ...

    //Calling
    flash.readByte(addressToReadFrom);
    //or
    flash.readByte(addressToReadFrom, FALSE);
    //yields the same results.

    ...

- However, when this argument is set to TRUE, it carries out the Fast Read instruction so data can be read at up to the memory’s maximum frequency.

    ...

    //Calling
    flash.readByteArray(addressToReadFrom, bufferToReadTo, bufferSize, TRUE);
    //instead of
    flash.readByteArray(addressToReadFrom, bufferToReadTo, bufferSize);
    // will result in faster read speeds for very large data arrays.

    ...

This is useful only when reading very large amounts of data from the flash memory. If used for small arrays or individual variables, it will slow down the read function.