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LaCie Slim DVD±RW Drive User's Manual
USB 2.0
4.4 DVD Capacity
There are important factors to consider when recording video, audio or data to DVD. The DVD media specification provides
for two physical sizes: 4.7" (12cm) and 3.1" (8cm) (both are .47" (1.2cm) thick). DVD discs can also be single-sided (SS) or
double-sided (DS), and each side can have one (SL) or two (DL) layers of data.
The amount of data or video that a disc can hold are dependent upon factors such as the amount of audio and the degree of
compression of the data, video or audio. For example, a single-layer DVD±R disc typically will store just over two hours of
MPEG-II video, but it is possible to put up to eight hours of VHS-quality video or one hundred sixty hours of audio on a
single-layer disc.
When media companies reference the amount of data that a disc can hold, they represent the total amount in terms of
gigabytes (GB), or a billion bytes (1000 x 1000 x 1000 bytes). This number, though, is not the way in which a computer
addresses the data; to a computer the value is binary and larger than a billion bytes – 1,073,741,824 (1024 x 1024 x
1024 bytes). Therefore, when you put in a 4.7GB DVD disc, the actual available capacity is 4.38GB; and a 8.5GB Double
Layer disc has an actual available capacity of 7.95GB.
Helpful Information
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