The size of a media block in bytes. This is a physical property of a media and returned by the corresponding media driver. This value is usually at least 512 bytes and always a power of 2. For some media types the meaning of this value is "the min. size of the aligned data buffer which write onto the media doesn't lead to read-modify-write operation." Therefore, reads and writes that are aligned on block boundaries and with lenght of a multiple block size can be much faster. Read and write operations on certain underlying media is done in blocks. A write operation that modifies only part of a block is less efficient, in general, than one that modifies an entire block. Data throughput degrades linearly for reads and writes in smaller sized units.

The size in bytes of a single file system cluster. This is a logical property of the file system. The file system organises and allocates the data on the disk in clusters where each cluster usually consists of one or more blocks. Cluster is a minimal unit that the file system allocates on the volume. Thus, a file of 1 byte length occupies 1 cluster.

Read and write operations that are aligned on cluster boundaries are more efficient from the file system point of view. In some circumstances cluster size can be less than a block size, but it is very inefficient.

This value is reported by a file system. The value less than 0 indicates a error.

The maximum file size that is supported by the file system mounted on this volume. Not all file system may report this parameter; The value KMaxTUint64 (0xffffffffffffffff) means that this particular file system hasn't provided this information.

The recommended buffer size for optimised reading performance.

The given buffer size is based on sensible benchmark testing results produced by the mobile device vendor. The buffer size is then added to the estart.txt file

The figure is included in the estart.txt file along with the drive number and the variable name. The example below shows the required format:

[DriveC] RecReadBufSize 8192

When no value is provided, value KErrNotSupported is returned.

The recommended buffer size for optimised writing performance.

The given buffer size is based on sensible benchmark testing results produced by the mobile device vendor. The buffer size is then added to the estart.txt file

The figure is included in the estart.txt file along with the drive number and the variable name. The example below shows the required format:

[DriveC] RecWriteBufSize 16384

When no value is provided, value KErrNotSupported is returned.