Disk Defraggers?
#2
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#3




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#4
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Why a 3rd party one? The built-in one actually isn't all that bad as defraggers go.
Slightly OT, why bother defragging? I've never found the performance benefit to be worthwhile. Then again, I reinstall more frequently than most and keep 30-50% free space on my HD, so that probably helps. But defragging was more of an issue when seek times were way slower and drives generally had lower performance metrics. I don't think it is nearly as significant an issue these days.
Slightly OT, why bother defragging? I've never found the performance benefit to be worthwhile. Then again, I reinstall more frequently than most and keep 30-50% free space on my HD, so that probably helps. But defragging was more of an issue when seek times were way slower and drives generally had lower performance metrics. I don't think it is nearly as significant an issue these days.
#5
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There was an article in Maximum PC a couple of months back which compared Vista's built-in defragger to a few third-party products. In all cases, they found that defragging only improved boot time; overall disk performance wasn't helped. That finding was consistent with what I've found in 10+ years of doing IT.
#6
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There is an outstanding open source solution -http://www.kessels.com/Jkdefrag/ which works beautifully, has been around for years, and includes a screensaver option so it can kick in and do some work when your machine is idle. Highly recommended.
#7
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However, the command line is a pain. Here's an add-on for a full GUI for jkdefrag that opens up the command line to all the fine tuning you desire. It's the full package, so kill your Kessels install if you have it.
http://www.emro.nl/freeware/
#9
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Back in the DOS days (and early versions of Windows), the system would read one file at a time, end to end. Combined with slow seek rates, this made defragging a big win.
However, XP/Vista will read segments of multiple files at the same time. Since it has to seek between files anyway, fragmentation is less of an issue.
XP/Vista also uses caching and prefetching to minimize disk access times. The Windows\Prefetch directory contains maps of frequently accessed disk blocks for different programs. When they start it loads those blocks right away rather than waiting for them to be demanded.
However, XP/Vista will read segments of multiple files at the same time. Since it has to seek between files anyway, fragmentation is less of an issue.
XP/Vista also uses caching and prefetching to minimize disk access times. The Windows\Prefetch directory contains maps of frequently accessed disk blocks for different programs. When they start it loads those blocks right away rather than waiting for them to be demanded.
#10
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I heard in Vista and XP it is a bad idea to run defrag as it puts all the exe files together.. the dll together etc.. but when a program needs to run it needs to search all over the HD to look for the said files
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I use jkdefrag also. I can't vouch for current improvements, but several years ago I improved the performance of an application for a client of mine from 3 sec. to 1 sec. response time with a defrag. This was with an older, client-heavy Powerbuilder app. jkdefrag just runs in the background - I figure it can't hurt.
#12
Join Date: Sep 2004
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I use Raxco PerfectDisk. No evidence that it helps. But it helps me sleep better at night knowing that I did my best. 
I edited a 40 GB MPEG2 containing 13 hours of TV programs, deleted the commericials and saved the resulting 13 separate 44-min MGPEG2s. I figure it can't hurt to defrag when you're doing stuff like that. Although having a lot RAM is probably a lot more important than defragging.

I edited a 40 GB MPEG2 containing 13 hours of TV programs, deleted the commericials and saved the resulting 13 separate 44-min MGPEG2s. I figure it can't hurt to defrag when you're doing stuff like that. Although having a lot RAM is probably a lot more important than defragging.
#13
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Back in the DOS days (and early versions of Windows), the system would read one file at a time, end to end. Combined with slow seek rates, this made defragging a big win.
However, XP/Vista will read segments of multiple files at the same time. Since it has to seek between files anyway, fragmentation is less of an issue.
XP/Vista also uses caching and prefetching to minimize disk access times. The Windows\Prefetch directory contains maps of frequently accessed disk blocks for different programs. When they start it loads those blocks right away rather than waiting for them to be demanded.
However, XP/Vista will read segments of multiple files at the same time. Since it has to seek between files anyway, fragmentation is less of an issue.
XP/Vista also uses caching and prefetching to minimize disk access times. The Windows\Prefetch directory contains maps of frequently accessed disk blocks for different programs. When they start it loads those blocks right away rather than waiting for them to be demanded.
So, when your program needs to access a file for data, it reads the MFT (which may be fragged itself and take disk seek time to get it all), which then tells the disk where to seek and read for the data file pieces. Which are then assembled for the program to use. That all takes time and disk cycles. Defragging puts those files together in as many larger, continguous sections as possible, in order to stop that extra disk thrashing.
That's why it works to improve performance. Program defragging is a good, but secondary purpose, and usually involves placing your most used programs contiguously towards the center of the disk where seek time is fastest. BTW, XP/Vista cannot "read segments of multiple files at the same time" because on a typical single disk system, the read-head has to be somewhere at any given time. It can't be reading the MFT and reading in other places on the disk and be in 2, 3 or more places at once.
#14
Join Date: May 2000
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I have a feeling, that your very interesting comments describe what is in the books (how it should be), not what really happens?!
BTW, Jeroen Kessels believes:
...Optimize:
On most harddisks the beginning of the harddisk is considerably faster than the end, sometimes by as much as 200 percent!...
On most harddisks the beginning of the harddisk is considerably faster than the end, sometimes by as much as 200 percent!...
Last edited by USAFAN; Aug 7, 2008 at 1:51 pm
#15
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That's because, once a program is installed on a clean disk (or on a defragged disk), the data bits that make it up will will tend to never move again. Unless a defrag utility sees that it is used often, then the algorithm will kcik in to move it. XP/Vista takes care of this automatically. Others will do it, too. Program updates to it could also frag it unless your disk is defragged, with lots of contiguous free space.
We work with (develop) high availability index and querying edgeware (software) that can write/update/delete gigs of data at a time. We've done multiple tests on defragging both single disks and RAID'ed sets for before/after MFT file sizes and their fragged extents, query times and contiguous free space before/after.
Defragging works -- that's why DiskKeeper (and others) are still in business. And that's why I use jkdefrag for personal use.

