Speed
Drive speed | Data rate | Write time for 80 minute/700 MB CD-R |
---|---|---|
1× | 150 kB/s | 80 minutes |
2× | 300 kB/s | 40 minutes |
4× | 600 kB/s | 20 minutes |
16× | 2.4 MB/s | 5 minutes |
20× | 3.0 MB/s | 4 minutes |
24× | 3.6 MB/s | 3.4 minutes (see below) |
32× | 4.8 MB/s | 2.5 minutes (see below) |
40× | 6.0 MB/s | 2 minutes (see below) |
48× | 7.2 MB/s | 1.7 minutes (see below) |
These times only include the actual optical writing pass over the disc. For most disc recording operations, additional time is used for overhead processes, such as organizing the files and tracks, which adds to the theoretical minimum total time required to produce a disc. (An exception might be making a disk from a prepared ISO image, for which the overhead would likely be trivial.) At the lowest write speeds, this overhead takes so much less time than the actual disc writing pass that it may be negligible, but at higher write speeds, the overhead time becomes a larger proportion of the overall time taken to produce a finished disc and may add significantly to it.
Also, above 20× speed, drives use a Zoned-CLV or CAV strategy, where the advertised maximum speed is only reached near the outer rim of the disc. This is not taken into account by the above table. (If this were not done, the faster rotation that would be required at the inner tracks could cause the disc to fracture and/or could cause excessive vibration which would make accurate and successful writing impossible.)
Read more about this topic: CD-R
Famous quotes containing the word speed:
“There exist certain individuals who are, by nature, given purely to contemplation and are utterly unsuited to action, and who, nevertheless, under a mysterious and unknown impulse, sometimes act with a speed which they themselves would have thought beyond them.”
—Charles Baudelaire (18211867)
“If it be aught toward the general good,
Set honor in one eye, and death ith other,
And I will look on both indifferently;
For let the gods so speed me as I love
The name of honor more than I fear death.”
—William Shakespeare (15641616)
“For myself and my loved ones, I want the heat, which comes at the speed of light. I dont want to have to hang about for the blast, which idles along at the speed of sound.”
—Martin Amis (b. 1949)