View Full Version : Off Topic CD speed
02-16-2004, 04:54 PM
In an earlier thread someone said that when the CD reader was looking at the interior of the CD, that speeds might only be 4X as opposed to the 48-52 whatever speeds that the player was rated for on the outside of the CD. It seemed to make sense. Rotation and seeking speed would be higher at the outside.
Would it make sense to "fill" the interior of a CD with something blank (a silent sound file). For instance your project was 300 megs. First record a 340 meg unused file to the master, and then burn your project next.
I am not computer literate (mostly macs most of my life), but is this an idea that could improve project play?
Hoping to avoid ridicule...
Yes, I think that is a great idea. Data CD-ROMS are recorded and played using CAV, Constant Angular Velocity, it spins at a constant speed like a record album. The pits and islands that contain the 1ís and 0ís that is your data, are evenly spaced. You can think of your data as evenly spaced marks on a piece of string. It takes a longer piece of string (more data) to make one revolution around the outer most track, than it does to make a revolution around the inner most track. So, your idea of Ďwastingí the slower inner tracks is a good one. The problem then becomes making sure that your files are placed in the correct order on the CD. Many (or at least some) CD burning software, let you specify which files have a higher or lower priority.
Iím lazy, so itís been a while since Iíve used any burning software other than what comes with WinXP. Iím not positive, but if I remember correctly, Gear Pro, Nero, Alcohol, and newer versions of Easy CD Creator, all let you have some control over physical placement of tracks. Other versions of CD writing software may also allow this.
(Note: This is a somewhat simplistic description, most CD-ROM drives actually use something called PCAV or Partial Constant Angular Velocity, but this is being Ďnit-pickyí and is more information than a person probably needs)
Here is a link to lots of information about recording CDís. Some of the info may be a bit dated, but itís a good link, and has lots of information.
02-20-2004, 12:56 AM
I don't think the difference in speeds between the inner and outer tracks (for lack of a better word) is that large. More like dropng from 48x to, say, 28x.
I could be wrong...and the best way to find out would be to run a performance test on the drive. But I don't think it drops down from 48x to 4x (unless there are scratches on the inner tracks or something).
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