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CD Recording FAQ
4. CD-R media
4.2. Media capacity
CD-R media have a capacity measured in minutes. This is the total time of audio which can be written on the cd (for an AudioCD). Alternatively, the equivalent in data is mentioned. For example, a 74min cd can hold 74 minutes of audio playback time, or 650MB of data.
The official cd capacity is 74 minutes. Improvements in optical technology
made possible the appearance of more formats, like the 80, 90 and 99min
blanks. Their capacities are shown in the following table:
|
Capacity in minutes
|
Equivalent in MBs
|
|
74
|
650
|
|
80
|
700
|
|
90
|
790
|
|
99
|
870
|
Apart from the 74min media, all other capacities stress a recorder's opticals, so not all recorders are able to use them. 80min media were a problem when they first appeared, and many recorders were unable to use them correctly, so some manufacturers decided to place restrictions in the firmware to disallow their use. Since then, the situation has been improved a lot and all decent drives will write 80min media correctly. Actually 80min media will offer faster performance.
90 and 99min media are the most recent addition. As was the case with 80 min media when they first appeared, not all recorders are able to use them, while some playback problems may appear.