Sophos SafeGuard Disk Encryption 4.60
Windows 2000 Professional SP4, Windows XP SP3
In NTFS 5 partitions boot encryption can take up to 1/2 an hour. Why?
It can sometimes happen that the Master File Table (MFT) is present in more than one location. However, all parts of the MFT must be encrypted so that all the relevant areas can also be encrypted. It may take a considerable amount of time to find all the parts of the MFT.
If the MFT is extremely fragmented, the hard disk areas between the parts of the MFT are also encrypted. For this reason it may happen that several GBs of disk space must be encrypted.