From GEAR Software Knowledgebase
The time it takes to record a disc is dependent on a number of factors including the recorder used, the type of media used and the brand of media used.
Note: When setting recording speeds using GEAR, the recording speeds available are based on what speed(s) the recorder can record at using the currently-loaded media. For best results be sure blank media is loaded prior to setting the recording speed.
CD-R & CD-RW Media
When recording to a CD-Recordable disc, the recording speed is mostly dictated by the speed of the recorder. This speed is give in 'X' where 1x equals a transfer rate of 150Kb/Sec.
|Data||Actual Size||Speed||Rate||Time (sec)||Time (min)|
These figures are approximate values, and the selected speed is not guaranteed for the duration of the recording operation
After recording a disc must also be 'fixated' as to allow the disc to be read in CD-ROM drives.
This process can add an extra 1 to 2 minutes to the recording.
For improved recording quality, most drive manufacturers recommend not recording CDs at speeds higher than 16x-24x and DVDs no higher than 4x.
CLV vs CAV
The above calculation only applies when recording at 12x or slower. This is because at these speeds the recorder will record at a consistent rate from start to finish.
This is known as CLV or 'Constant Linear Velocity'.
When recording at higher speeds, the drive will actually record at an accelerated rate, reaching the maximum speed only at the outer rim.
This is known as CAV or 'Constant Angular Velocity'.
Therefore recording at 52x may only give an average recording speed of 42x or less. Each drive will result in a different average recording speed.
Media Quality: The quality of the media can also limit the available recording speeds.
Most recorders will be able to identify the media being used and limit the recording speed accordingly. Therefore when using some media a 52x drive may limit the recording speed to 32x.
The speeds a piece of media is qualified for is often listed on the packaging.
DVD recording is practically the same as recording to CD. However there are a few differences.
1x on DVD is defined as 1350 Kb/sec. CLV recording is done up to 4x DVD. Any faster speeds use CLV. DVDs do not require finalization. Recording to DVD-R & DVD-RW require a track to be 'reserved' prior to recording. This process can add up to a minute or more to the recording time. Recording to DVD+RW requires the disc to be 'formatted' prior to recording. This process can up to 20 seconds or more to the recording time. The 30mm rule: When recording a relatively small amount of data to a DVD, the recoding time may be much longer than anticipated. This is due to the 30mm rule.
The DVD standards require that for a DVD to be compatible with the majority of DVD-ROM and DVD-Video players, at least 30mm of the disc's surface must be recorded to. This is approximately 1GB of data.
When less than 1GB is recorded, the track on the disc will be extended to the 1GB limit. When recording to DVD-R or DVD-RW media this 'padding' of a track is done automatically by the drive. On DVD+R or DVD +RW media this is done by GEAR and only when recording DVD Video titles.
The 30mm is to be measured from the center of the disc hub - not the recording surface.
Other factors: The system used to record can also influence the recording speed.
Some older systems may not be able to transfer the data from the hard disk to the recorder as fast as the recorder can record the data to the disc.
This can be caused by using older hard drive technologies, not enabling DMA transfer, fragmentation of the disc, recording from network drives, running other applications simultaneously and other such factors.
Also the interface used to connect the recorder can be a factor. When connected to a USB1.1 or parallel port, the limited transfer rate of these connections will limit recording speed greatly.