What determines defrag speed?

I haven't defragged my hard in a long time and reason being is that every time I defrag it takes 7+ hrs (some times 12...). So I wanted to know what makes it so slow? Is it because I only have 3.5GB of free space on my 20Gb harddrive? Or is speed determined by CPU, and RAM?

BTW: I have a P4 2GHz, 1.2GB of RAM, and a 20GB harddrive (with about 3 GB free space left).

 

Ah...nice PC. Anyway, the defrag speed is influenced by the speed of the HDD and the fragmentation itself. Also, a great deal of influence when defragmenting is the size of the fragmented files. Larger files are being moved faster than smaller files (since the small ones usually are too many).
What are you using?

 

What determines Defragmentation is many things.

Mainly, your hard disk rotation speed, measured in RPM (rotations per minute). Some hard disks spin at 7200 RPM, the really old ones spin at 5400 RPM only, and Raptors hard diks spin at 10,000 RPM, SCSI hard disks spin at 10,000-15,000 RPM. So that give you an idea. having a 7200 RPM with good cache memory is good enough.

Secondly, your CPU and RAM also play a role in this.

 

I disagree. The combination of available disk space and the level of fragmentation is the main reason for slow defragmentation. Spindle speed has little to do with defragmentation.

 

someone please confirm what he said.

 

The speed of the HDD is important, but that's not the only reason for a slow defragmentation. kegobeer, you have made a good point, but only partially. Like I've said, it depends on the HDDs speed to, but also on the degree of fragmentation and the size of the fragmented files. It takes less time to defragment a drive full of music than the Windows drive.

 

spindle speed does influence defrag times up to a certain point. faster spindle speed = faster read/write times but the real bottleneck will be the actuator arm which controls the read/write heads which will be dependent upon cache on the HD and ram.

 

I don't understand what the size of the RAM has to do with the defragmentation process. The HDD cache is obvious, but even so there are HDDs with 32MB of cache that perform slower than ones with 8MB, so you haven't made a point there. Anyway, cache is important, but more cache doesn't mean more speed. Filling up the cache with small files which aren't accessed too many times (like in the case of a defragmentation) can slow things down.

 

Spindle speed *also* plays a big role when defragging. A lot of things do. I doubt CPU speed have much to say, and RAM speed might not make a noticeable difference either, but everything related to the harddrive certainly makes a big difference.

A few factors:
- Amount of free space (if the disk is almost full, defragging takes a lot longer)
- Disk speed (RPM, latency and bandwidth)
- Level of fragmentation (the more fragmented your file system is, the longer it takes to defrag)
- Size of the partition (bigger partitions means more data to defrag)

Edit
And of course the defrag program you use also makes a big difference, as said below.

 

The defrag program itself can make a difference. If you're still using the Windows app, you might want to consider a freebie like Auslogics Disk Defrag.

 

Yeah Jalf, that would be it. But the speed part is obvious. However, it's not the general speed that matters (kinda like HD Tune), is the speed of moving small files.
I used PerfectDisk and liked it. I've grown to love a silent HDD and not waste space doing defrags.

 

Sadly its a 5400rpm IDE harddrive with 2mb cache...also I've tried Windows defrag, O&O, and Diskeeper but they all are really slow.

 

Try PerfectDisk. Maybe it will work better for you.

 

If you want to speed up defragmentation, you'll need to increase free space on your drive. Unless you have a drive full of really small files, you just simply don't have enough free space available to do the required file swaps.

 

I have an idea....when you use vista defragger, two processes start running in task manager. The priority of those processes is set to LOW and BELOW NORMAL....set these to normal or above normal and tah dah! faster defrag.

 

Good tip. You could also try this: http://www.windowsvistaweblog.com/2007/03/24/tips-defrag-windows-vista-faster/

Now, I have a 60GB drive with two partitions, with a total of just over 30GB of files, so my defrag speeds are fairly quick. However, it's much faster than the included Vista defrag utility. Since it's free, it might be an alternative, and it works with XP (just skip steps 1 and 3).

 

And you've tested that this makes a difference?

The thing is, if no other process need the CPU, then processes running at below normal or low get all the CPU time they need. So if you're just sitting at the desktop, changing the priority shouldn't make a noticeable difference. (Of course, if you're playing games or such while defragging, changing the priority will make a big difference, because suddenly the game is only given the bits of CPU time left over after the defragger

 

I would much rather recommend jkDefrag GUI (in my software thread). I've been using it for a little while now and it's made my system considerably faster.

 

Well actually I'm still using Windows XP, so yaaa....I can't really delete anything since I onyl have about 4GB of music, documents etc...and the rest of my 40GB are like programs. *Sigh* ...I need a bigger harddrive

 

A defrag program doesn't delete anything, it just moves it to it's optimal place. Remember tetris? That's what it does with your system files.

 

LOL... Great analogy!

 

It's the only way i could think of it.

 

I thought if there were more space on my harddrive it would defrag faster.

 

In theory, yeah, but it depends on how fragmented your drive is. Speed should be the last thing on your mind, quality is what you should be worried about.

 

To answer the OP, the speed of defrag depends on a number of factors such as (not in any order)
-extent of overall file fragmentation
-size of fragmented files and number of fragments
-available free disk space
-the efficiency of the defragmenter's algorithms
-the defrag mode (eg: does it it include free space consolidation, file placement etc)
-whether there are other programs running simultaneously during a defrag
-Hardware: CPU speed and harddrive speeds primarily

The easiest, most efficient, and hassle-free way to defrag is with an automatic defragmenter. Why waste *your* time staring at blocks on the screen, when the defragger can do everything on it's own, in the background, without any intervention.

 

Defragmenting should be done when you're not using the computer. That's the fastest and the less annoying way.