No offense intended to anyone, it's often human nature to follow the crowd, & that's true with software too -- lots of comments so far today talking about a few favorite defragging apps that to me seem to send the message: "Why bother with today's GOTD"? Well that happens often enough it shouldn't deserve or attract any special attention, except in this case I think there's a bit more crowd following than usual, which might lead to fewer people giving Amigabit Disk Defrag a fair try. Maybe it does better, maybe it does worse, but the way to find out if a defrag app's optimizations suit you is to try it. I know I've tried a few of today's favorites & found them sorely lacking *for me*, the way I use this PC.
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If it helps... AFAIK most defraggers use the built-in Windows API -- they analyze the files on a hard drive partition, then tell Windows to move what, where. Some will work with the hidden 1st track, e.g. Paragon & MyDefrag, some will work with Windows' files that are normally in use [by defragging them during a re-boot before Windows starts], e.g. Ultra Defrag, and most use an optimization strategy [sometimes they'll have several to choose from] that puts the files you use most often on the fastest portion of that drive/partition.
[Std. hard drives use a spinning platter (or platters) to store data -- for one revolution of the disc, the drive heads pass over (can read/write) more data on the outer edge than the inner because the circumference or distance is greater on the outer edge than the inner.]
The big questions are: *What files do you use most often, & what do you want sped up, e.g. Windows' start times or an app [or apps] that does a lot of reading from the hard drive"? MyDefrag evolved into a script interpreter that lets you write you own script or procedure, but otherwise it's up to the developers to make their best guess, to figure out what makes the most people, the most potential customers happy. There are a lot of things that influence how well people like one defrag app vs. another, but from a purely practical results standpoint, the best defrag software is the one that's figured out how to speed up the stuff *You* feel is most important to *You*.
Beyond that all defrag software takes the small portions of data that makes up a file & makes sure they're next to each other rather than being scattered across the hard drive's platter(s) -- it's physically less work that way because the drive heads that do the actual reading don't have to jump all over the place, from the outer edge to the inner & everywhere in between. That's also an obvious advantage of SSDs, which have no moving parts. [Trivia Note: the same thing applies to CD/DVDs/Blu-Ray discs -- there you don't have to worry about fragmentation so much, but a less well designed video DVD for example will have the player or drive skipping back & forth between the inner & outer edges, helping to make playback seem unresponsive.]
Generally all data is moved towards the start of the drive partition because that's where things are faster, & that's why you want to defrag a partition before you do something like shrink it, cutting off or trimming some of the free space at the end of that partition. That's not to say all the data on a hard drive partition is tightly packed after you defrag it -- hard drives have steadily become larger & faster, so a) a more complete defrag takes longer, & b) you're less likely to notice if the defrag was not 100% complete. If a defrag app seems especially fast, it could be that the code or methods of analyzing your files is better/faster, or it could be that it doesn't move as much data around as the app(s) you compared it to -- as long as a the pieces of a file are next to each other, you'll likely not notice any difference if it's in the middle of the partition or packed in at the beginning, so defrag apps aren't equally aggressive about packing all that data at the front of the disk/partition. TO most people that won't matter a whole lot -- just be aware that if one defrag app seems a lot faster, maybe it's because that app is doing a lot less work... MyDefrag is up front about it, giving you the choice between quick & thorough, but for some apps it's just one way that they cut corners & maybe you should look for the other shortcuts they've taken?
That all said, recent tech expands on the idea of making access to certain files faster... A Hybrid drive [a smaller SSD tacked onto a std. hard disk] takes the files you read most often & copies them to the SSD portion as a sort of ready cache -- if you regularly do the same thing with your PC/laptop, it can make a big difference. Some Intel-based motherboards let you do the same thing using a small, sometimes special SSD for the cache regardless what kind or brand of hard drives. And some Intel motherboards let you set up a relatively small cache on a larger SSD where data's stored when your PC/laptop goes to sleep, making wake-up faster.
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#12: "Does Defraging a PC greatly increase the speed of a slow running PC, I’ve read conflicting reports on this?"
*Maybe*
Obviously it has no effect if you're only using SSDs, but beyond that it's a matter of in the course of using your PC are things slowed down by reading highly fragmented files? You can have 100 GB of very badly fragmented files, but if they're all video's you never watch, the fact they need defragging is irrelevant. The Windows folder OTOH may take up less than a quarter of that space, but if it's badly fragmented you should notice an improvement after defragging it.
It's all about the files you use regularly. The one file that most every Windows PC always uses is the swap file, yet because Windows always uses it, that file gets skipped by a defrag in Windows. While there are other methods, here's a Microsoft article on handling that, though it's written for a purpose other than basic maintenance http://support.microsoft.com/kb/2533911
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#13: "Any of you out there please benchmark before and after installing software that is supposed to speed up your computer. That would be real criticism."
And thus you hit the problem of comparing defrag apps [at least their results] squarely on the head. :)
You might try to compare thoroughness of the defrag operation, but you'd have to do something like clone a HDD to another drive, then defrag both & compare -- otherwise your start conditions wouldn't be the same. Since different apps use different strategies, move different files to the faster front of the partition, any comparison there would be Apples & Oranges -- the same for any speedup, since the files & apps you use most often are not the same as mine.