Disk defragmentation

Fragmentation is a fact of life with the Windows operating systems and although you may not know that it is a problem, slow downs in system performance can occur because of fragmentation.  Files can be split into hundreds of pieces and spread out over your drive without you even knowing it.  The larger the number of "pieces" or fragments the longer it takes to retrieve a file.  Seeking to find the information in the file causes head movement, typically one head move for each fragment which increases latency.  It also increases wear on the drive head mechanism.  I/O performance is usually the cause of slowdowns and even though processors are getting faster and faster, hard drive throughput has not had the same kind of monumental leaps.  Defragmenting your hard drive can improve I/O throughput, because the disk only needs to move one time to retrieve an entire file.   This file can be read sequentially without incurring head movement, i.e. improved access times.

Microsoft has included an improved disk defragmentation program in Windows XP, but even it is not perfect. You may care to try BuzzSaw. Buzzsaw defragments on the fly and is totally free and registration is not even required.  This program runs at idle priority so you can continue working without Buzzsaw using your valuable CPU time. It watches the drive for modified files and waits approximately 60 seconds before defragmentation begins. It waits, because you may be downloading a file, etc. and there is no need to defragment the file if it is going to be modified again shortly. If you are a developer, you may be compiling files, or saving files frequently which is another reason for delayed defragmentation. Version 2.0 decreases I/O issues by only defragmenting when the disk is greater than 95% idle. It runs minimized on the task bar, so don't be alarmed if no window is shown on the screen. You can maximize it by right clicking on the fly lure in the task bar. It is available from http://www.dirms.com.