Originally posted by JohnDoe
[B]My question is how fast is the rotation of CD-Drives in the inner circle and on the other end of the CD not the daterate in kB/s, the rotations per second.
And the same on DVD-Drives
Where is the end of the technical solutions [/B]
The RPM (motor spindle) at the hub and the outer periphery of a disc is the same when a disc is recorded or read using CAV (constant angular velociity). The velocity is much greater at the outer periphery because of the greater distance travelled during each rotation of the disc.
Some statistics using a CD(R) with a scanning velocity of 1.2 meters/sec.:
Data track length on an 80 minute disc - 5,760 meters (3.58 miles)
Rotational velocity @52x - 62.4 m/s (140 mph)
Rotation frequency in CAV mode @52x - Approximately 10,000 - 10,400 RPM
Some DVD statistics with a scanning velocity of 3.49 meters/sec. (single/side layer disc with 4.7 GB capacity):
Nominal data track length on a 133 minute disc - 27,850 meters (17.3 miles)
Rotational velocity @16x - 55.84 m/s (125 mph)
Rotation frequency in CAV mode @16x - Approximately 9,300-9,600 RPM
See DVD Technology
and DVD Physical Parameters
It is highly unlikely that current speeds of 52x for CD-R and 16x for DVD will increase. Beyond these speeds, there are manufacturing and mechanical stress limit constraints with media. There are also heat related and safety issues with high speed operation in a record/playback device.