CD Recording FAQ

2. The CD Recorder
   2.5. Recording speed
 
    2.5.1. Speed ratings

A cd recorder comes with three speed ratings:

• A speed rating concering cd reading, which is not too accurate (as is always the case with cd readers these days). If the cd recorder can also read DVD discs, another speed rating for reading DVDs is given
• A speed rating concerning writing on cd-rewritable (cd-rw) media. This speed is the maximum speed the drive can use a cd-rw disc at, when using it as a cd-r disc. A recorder can use such media only if its laser mechanism supports it.
• A speed rating concerning writing on cd-r media.

The speed for cdr media comes first, the speed for cd-rw media follows, and the speed for cd reading comes last.

For example, 8x2x20x means that the drive can record on cdr media at 8x, record on cdrw media at 2x, and read a cd at a maximum 20x. The first two speeds are always strictly defined, while the third one will not be necessarily true.

The unit for these speed ratings is 1x, which represents a data rate of 150KB/sec. The following table shows the data rates and times needed to write a 650MB cd for various speed ratings.

    2.5.2. Which speed is better?

A recorder able to write at a maximum speed of x can also write at lower speeds. The selection of speeds available depends on the firmware and serves a role of an alternative in case of trouble.

For example, an 8x recorder is able to write at 1x, 2x, 4x, 6x and 8x. If the computer is not fast enough for 8x recording, you can try lower speeds. Also, in case the media you use is not capable of 8x speed, you can try lower speeds like 4x.

Apart from this scenario, often people believe that recording at lower speeds results into recordings of higher quality. Audio cds are supposed to be superior when written at 1x and often people insist that their cds are played back properly on stand alone cd players only when recorded at low speeds.

All these may rise questions regarding the right speed to record at.

A recorder capable of a maximum speed of 8x is optimized for recording at this speed. Recording at lower speeds means that the recording process lasts longer, thus generating more heat, which lowers the quality of the final cd and stresses the drive.

On the other hand, a drive of lower quality may not perform well at its maximum speed due to a number of reasons. Bad design resulting in mechanical instability when the blank cd rotates at 8x may be one.

To summarize, a quality drive will not have any problem operating at its highest speed. On the contrary, its maximum speed is also the optimal one. However, a drive of lower quality may show an erratic behaviour, obliging its user to select a lower speed, especially for audio cds.

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