Ask Flash: How do I know if my DVD burner burns at the correct speed?

When 16x DVD writers came out all the manufacturers claimed fastest burning speeds and NEC actually claimed that it would burn a DVD in under 4 minutes I disputed this in my review and feel we were all misled by this marketing hype. It is accepted that 1x speed burning will take 1hour to burn a DVD. So from this we can deduce the following times for single layer DVD media Burning Speed Expected Burn Time Burn Time Achieved 1x 60 minutes 60 minutes 2x 30 minutes 30 minutes 4x 15 minutes 15 - 16 minutes 8x 7.5 minutes 8 -10 minutes 12x 5 minutes 7 -9 minutes 16x 4 minutes 5 - 7 minutes 18x 3.3 minutes 5 - 6 minutes Dual layer media burn times are approximately double the above times and currently the burn speeds are slower. As you can see the actual burn times against expected burn times increases as the burn speed increases this is because when the drive starts burning it cannot burn at the full speed and has to build up from a slower speed of 4x 6x or 8x achieving the maximum speed only at the end (outer edge) of the burn. The drives have various ways of achieving the maximum speed CAV, CLV, PCAV, & ZCLV these are explained in my article here and the speed transition points can have a great effect on the actual recording times. I have found that the LG drive burning at 16x speed is quicker than the Samsung at 18x speed. & in my opinion 18x burning is a myth until such times 18x speed can be achieved earlier in the burn. The following two graphs show my point that 16x can be faster than 18x 16x burning with LG took 5 mins 16 secs 18x burning with Samsung took longer at 5 mins 40 secs There are other factors governing burning time such as disc initialization which can be from a few seconds to a few minutes, burn quality control can increase the burning time whilst the drive selects the optimum burning speed, buffer under-run caused by external processor usage restricting the file transfer speed. Although I test all my drives at maximum burn speed I prefer to burn at 8x speed which I find tends to result in a better quality overall burn

Added:  May 9th 2007
Reviewer:  Flash
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