How is CD-R CD-RW recording speed determined?

[Zoon]

How does the computer know what recording speed to use with a CD-R or a CD-RW disc? I was setting the recording speed for a CD-R when I was told that the software knows the correct speed for any disc. Do I set the speed or is speed selection automatic?

 

[Jontmke]

When I use Roxio it queries the cd itself for its speed. It must have some data on it somewhere.

Jon

There is much pleasure to be gained from useless knowledge. (Bertrand Russell)

 

[jsauce]

Basically what happens when you place a blank cd in a cd writer is that the cd writer examines the disk. This is how it determines its blank-recordable and not just blank-read-only. It looks at the Disk's ATIP (Absolute Time In Pregroove) which stores the maximum time of the disk as well as its minimum and maximum burn speed. Now manufactuers do not have to include this feature in the ATIP which will leave you free to try and burn at your burner's max speed, but this can cause a problem if the disk cannot handle it. Normally you want to set your CD-burning software to the max allowed by the disk manufactuer. Thankfully however most burner software will not try to burn faster than the disk can handle even when you set it to the burner's max. It will instead burn to the max speed of the media.

John D. Saucier
jsauce@magicguild.com
Certified Technician
Network Administrator