Specification Sheet

4
Fragmentation level
The level of fragmentation serves as the basis for running the desired action. It will often be used
as a threshold above which defragmentation should be started. In this way it only stands to reason
that a computer doesn‘t need to be defragmented when its fragmentation level is below 1%. This
is how both O&O Defrag and the Windows Defragmenter function. There is, however, one major
difference.
Because we’re discussing a percentile value, its calculation – more precisely, the basis for
its calculation – is of decisive importance. In order to determine the level of fragmentation,
O&O Defrag considers the file’s size as well as its number of fragments. Working this way, a large,
heavily fragmented file gets more consideration than a small file that is only slightly fragmented.
In a similar way, defragmentation will only begin when a large (and therefore important) file is
fragmented, although all other files are already defragmented. This is extremely important for server
systems with a Microsoft Exchange or SQL database.
Compared to what was just described, other defragmentation products – such as the one integrated
in Windows – limit themselves to counting the number of fragmented files and adjusting them to
the total number of files. This is a simple and certainly comprehensible method, but one that is really
ineffectual in practice. If you imagine a normal Windows system with approximately 150.000 files
that are all defragmented, a single fragmented file would never activate a defragmentation. Not
even when it involved a 12 GB offline file from Microsoft Outlook consisting of 8.939 fragmented
files.
Defragmentation in one run
O&O Defrag works with a so-called “single pass“ strategy. This means that one single execution is
enough for achieving a complete and thorough defragmentation and consolidation of all files. This
kind of behavior is labeled “deterministic“ in information technology, i.e., the result is – depending
on intervening changes in the file system – predictable. Or to put it another way: Once O&O Defrag
defragments a drive, that drive is defragmented.
The Windows Defragmenter uses a “multi pass“ strategy. As the name indicates, multiple executions
are needed in order to achieve an optimal result similar to that of O&O Defrag. The number of these
executions is not predictable because they are based on a vague observation of the overall file status.
Or put another way: After one execution, the Windows Defragmenter is still far from finished.
The problem that arises from this is obvious: if a company-wide defragmentation is planned on
many computers, there’s no way to know whether these computers are truly and completely
defragmented when the Windows‘ defragmentation has finished. Maybe they still need to be
defragmented a couple more times? But when should this be done? And when that finally happens,
maybe the level of fragmentation has increased once again so that you’ll have to begin right from
the beginning. An end to the whole misadventure is nowhere in sight!
O&O Defrag provides a clear and well-defined flowchart for defragmentation: it defragments all
fragmented files and offers an option for consolidating free disk space.