How do I go about increasing defrag speed?

Question

I'm running a defrag on a friend's laptop which is horribly fragmented and it is taking an age. Would killing any unnecessary running processes increase the speed of the defrag or is the bottleneck the HDD speed?

Regardless of the answer above, what can I do (if anything) to increase the speed of a disk defrag?

Answer 1

Starting with Vista also IO calls have priorities. By default the defrag runs at very low priority. You can use Processhacker, to set the IO Priority of the defrag tool to high:

This improves the speed a bit.

Answer 2

You absolutely should kill any running processes, as anything writing to the disk while a defrag is occurring can interfere with the process, and make it take longer.

Obviously, a faster HDD will defrag faster (with the best choice being an SSD), but you should see decent gains just by closing all other non-system processes.

Answer 3

To defrag or not to defrag?

• Do you even need to defrag? While defragging strictly when needed will give a moderate performance restoration, disk fragmentation is rarely the cause of performance issues in modern computer systems - you have to have either a very full disk or a very atypical workload, as Windows, OS X, and Linux all try to avoid creating significant fragmentation. If you defragment more than once every month or three, you'll probably never improve performance enough to recoup the time spent waiting to defragment, much less the wear and tear on the hardware. If the operating system's defragmenting tool says the drive isn't fragmented enough to defrag, listen to it and look for another cause behind poor performance.
• To put it another way: If you "need" to defrag more often than every 1-3 months, something else is probably to blame for poor performance, and your perception that defragmenting helps is most likely the placebo effect. Focus on finding the real problem.
• Windows 7 and Windows 8 automatically defrag once a week as needed, Check task scheduler, make sure the computer is left on during the time it wants to do this (adjust the time as necessary), and then don't worry about defragmenting at all.
• Defragmenting is only for spinning platters, not SSDs or other flash media like thumb drives and SD cards. No matter how fragmented it may appear to be, defragmenting an SSD will be slow, ineffective, and will shorten the life of an SSD.

Problems that can slow down degragementing

• Do you have enough free disk space to defrag? Give or take a bit, You need around 20% free disk space for defragmenters to work efficiently.
• Make sure your anti-virus or other security software isn't getting in the way. Look in task manager as you start defragmenting and see if anything else shoots up in CPU time during the defrag process.
• Other running processes will have an impact, because of disk access (both reads and writes will compete with the defragmenting process), virtual memory (again - disk access), and CPU/memory usage.

Problems and behaviors that lead to recurring fragmentation

• Full hard drive. The fuller the hard drive, the less effective the operating system's techniques for stopping disk fragmentation will be. Try to keep at least 20% of your drive free.
• Frequent creation and deletion of large numbers and/or large sizes of files. Atypical usage, like non-linear video editing, frequently ununstalling software to make room for other software, etc - basically, if you constantly have to free up space on your hard drive, you are probably dealing with a lot of fragmentation.