To defrag or not defrag - that's the question

Erik_Nygaard wrote on 10/29/2002, 11:31 AM

There's an interesting discussion at Prorec wich basically concludes that you should not defrag your audio drive.

http://www.prorec.com/prorec/prorecording.nsf/all?openview&count=200

AnalogX has a free interleave utility that fragments your waves (in an orderly fashion) to improve disk reading. There's some info there that's also in favour of not defragging.

http://www.analogx.com/contents/download/audio/interlv.htm

Now, the manuals for both Vegas and Sonar actually recommend defragging your audio drive on a regular basis, pages 326 and 557 respectively.

Can we please have a simple yes/no if possible?
I understand that audio files may get fragmented in non-optimal ways audiowise, but won't fixing this with a defrag utility break other "healthy fragmented" files?

I'm planning on moving my audio files out of their project folders and use AnalogXs interleave utility to copy them back into the folders, keeping the originals as backups.

Erik

Comments

edna6284 wrote on 10/29/2002, 12:11 PM

I defrag all the time, and continue to do so...despite the trendy claims to the contrary.

It makes logical sense that, when grabbing information, the most logical place for the next sequential bit of information is as close to the preceding one as possible.

At least that's the logic I use... :) D

vanblah wrote on 10/29/2002, 2:26 PM

Say you have a hard drive with 1MB clusters, now say you have an 8MB audio file. The file will be stored in 8 clusters on your hard drive. If you defrag the hard drive (a modern hard drive anyway) those clusters will indeed become contiguous: lined up like 12345678. In the old days, it was necesary to interleave a file because a cluster might go past the Read/Write heads faster than a controller can get the data to the CPU. Interleaving just means locating the clusters around the disk in a logical fashion to minimize the movement of the R/W heads: 15263748. As drives and controllers became faster "they" did away with interleaving, so now when you defrag everything lines up.

Now we are pushing the limits on these so-called fast drives and controllers with multiple streaming audio files. These files are huge so you know they are going to be stored in several clusters on a disk, not only that but there is more than one file at a time being read (and written in the case fo recording). If a file is contiguous (12345678) there is the possibility that a cluster gets skipped due to CPU bottle-necking or just bad CRC (error checking). And the more "takes" you do the worse it gets, especially with multiple files making up one track (using a "best of" vocal arrangement for instance). So we go back to interleaving ...

Arnar wrote on 10/30/2002, 2:44 AM

i have no scientific data to back me up but i have had projects that i couldnt run after defragging.
So i went and got Analog X interleave and that worked!

Erik_Nygaard wrote on 10/30/2002, 9:05 AM

Thanks for the info.
I have not heard any difference testing my interleaved vs defragged waves,
but then my projects are still fairly small, 10-12 audio tracks,
so I obviously have not hit the ceiling were interleaved may make a difference.
And I always render to a new track when comping 4-5 takes anyway.

TeeCee wrote on 10/30/2002, 10:42 AM

When you "hear" the difference, it will be a drop out, stutter, or halt. Not a subtle loss in quality.

TeeCee