CD and DVD Writing Speed - Theoretical Versus Practical Writing Speed

Theoretical Versus Practical Writing Speed

Almost all of the modern CD/DVD burning software support selection of the speed at which the portable disc is written. However, the option a user chooses only defines the theoretical maximum of disc burning process. There are other factors that influence the time taken for a disc to be written to:

• Resources available to the program: Reading or writing data on a disc consumes moderate to high level of system resources (including memory and CPU resources), and running other programs at the same time may force the CD/DVD drive to choose a lower speed automatically, to accommodate with the available resources.
• Disc quality: Optical disc recorders detect the available speed options based on the data which is available on the disc itself; however, some low quality discs make a high speed option available to the software, while the burning process can never reach that speed in practice.
• The reading and writing process may not happen at a steady speed. CD drives and many early DVD drives stored data with constant linear velocity, so that the data rate remained the same regardless of the position of the optical head; however, modern DVD drives use Zoned Constant Linear Velocity with different data rates in different zones.