12x, 16x, 20x Or Faster?
Many people associate these numbers with speed, which is correct, but they are not aware of what these numbers actually stand for. They are derived from the standard rotation speed of a music CD (1x), which has a data transfer rate of 150 kB/s. Based on this, you get the following figures and rates:
- 12x drive, 1,800 kB/s transfer rate
- 16x drive, 2,400 kB/s transfer rate
- 20x drive, 3,000 kB/s transfer rate
From here, you can arrive at the following recording times (for a complete CD):
- a 12x drive, 6:30 minutes
- a 16x drive, 4:50 minutes
- a 20x drive, 3:50 minutes
As you can see, the differences in recording times for the various models is much less than their multiplying factors for speed might suggest (i.e., a 20x drive is not 8 times faster than a 12x drive). Instead, these multiplying factors refer to the data transfer rates. There are other factors that affect the speed of a CD-R, which also bear consideration. First of all, every CD has a lead-in and a lead-out area that must also be written. In addition, the data has to be prepared by the recording software before the actual write process can begin. This process, in turn, depends on the performance of your system, which affect the write times accordingly.
