Installation and System Requirements - O&O Software

Size of Drive
All drive sizes supported by Windows are supported by O&O Defrag.
O&O Defrag 11 was optimized for use on file systems having an especially large number of
files. The storage capacity of a drive is therefore irrelevant.
Directories
Any number of directories can be defragmented. O&O Defrag has an optimized memory
management which allows it to record all file and directory information.
Free Hard Disk Space
Drives without any free disk space cannot be defragmented. For the best possible results, at
least 5% of the whole hard disk capacity should be free. It might not be possible to defragment
files larger than the available free and contiguous disk space.
To speed up the defragmentation process, we recommend you keep about 10 to 15% of
free space available on your hard disk, although the larger the hard disk, the smaller this
percentage will be. What really matters is the size of the largest file which needs to be
defragmented or moved around- for a file like this, you must have enough contiguous free
space available.
User's Guide for O&O Defrag 11 Technical Information l 47