Version Information

Quick Format 
If unchecked, each sector of the new volume will be formatted. This means that the new volume 
will be 
entirely
filled with random data. Quick format is much faster but may be less secure 
because until the whole volume has been filled with files, it may be possible to tell how much data 
it contains (if the space was not filled with random data beforehand). If you are not sure whether to 
enable or disable Quick Format, we recommend that you leave this option unchecked. Note that 
Quick Format can only be enabled when encrypting partitions/devices.
Important: When encrypting a partition/device within which you intend to create a hidden volume 
afterwards, leave this option unchecked. 
 
Dynamic 
Dynamic TrueCrypt container is a pre-allocated NTFS sparse file whose physical size (actual disk 
space used) grows as new data is added to it. Note that the physical size of the container (actual 
disk space that the container uses) will not decrease when files are deleted on the TrueCrypt 
volume. The physical size of the container can only 
increase
up to the maximum value that is 
specified by the user during the volume creation process. After the maximum specified size is 
reached, the physical size of the container will remain constant. 
Note that sparse files can only be created in the NTFS file system. If you are creating a container 
in the FAT file system, the option 
Dynamic
will be disabled (“grayed out”).
Note that the size of a dynamic (sparse-file-hosted) TrueCrypt volume reported by Windows and by 
TrueCrypt will always be equal to its maximum size (which you specify when creating the volume). 
To find out current physical size of the container (actual disk space it uses), right-click the 
container file (in a Windows Explorer window, not in TrueCrypt), then select 
Properties
and see the 
Size on disk 
value. 
WARNING: Performance of dynamic (sparse-file-hosted) TrueCrypt volumes is significantly worse 
than performance of regular volumes. Dynamic (sparse-file-hosted) TrueCrypt volumes are also 
less secure, because it is possible to tell which volume sectors are unused. Furthermore, if data is 
written to a dynamic volume when there is not enough free space in its host file system, the 
encrypted file system may get corrupted. 
Cluster Size 
Cluster is an allocation unit. For example, one cluster is allocated on a FAT file system for a one-
byte file. When the file grows beyond the cluster boundary, another cluster is allocated. 
Theoretically, this means that the bigger the cluster size, the more disk space is wasted; however, 
the better the performance. If you do not know which value to use, use the default.