Editing CD-R (section)

==Speed==

{| class="wikitable"
|-
!Data writing speed
!Data writing rate
!Write time for 80 minute/700&nbsp;MB CD-R
|-
|1×||150 [[Kilobyte|kB]]/s||80 minutes
|-
|2×||300 kB/s||40 minutes
|-
|4×||600 kB/s||20 minutes
|-
|8×||1.2 MB/s||10 minutes
|-
|12×||1.8 MB/s||7 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)
|-
|52×||7.8 MB/s||1.5 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 disc 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 [[Constant linear velocity#Zoned Constant Linear Velocity|Zoned-CLV]] or CAV strategy, where the advertised maximum speed is only reached near the outer rim of the disc.<ref>{{cite web|url=http://cdspeed2000.com/faq.html#4 |title=Explanation of CLV, CAV, P-CAV and Z-CLV with diagrams |publisher=Cdspeed2000.com |access-date=2011-12-16}}</ref> 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.)