Burn speed increases across the disk

[rotty]

I have a laptop with a built in dvd multidrive. I also have a Sony external USB burner.
When I use the external burner, the write speed stays the same (whatever setting you chose) throughout the entire write to disk.
If I use the built in burner, the write speed starts slow and then jumps up in stages thoughout the disk. You can see the different burn speed effects on the disk itself.
I know this is done on purpose in the firmware, but am I better off using the constant speed external burner.
Also I can guess why this is done but can anybody tell me the reason.
Thanks.

[atreides93]

Check out this website...talks a bit about CAV vs CLV

http://telcontar.net/Misc/maths/CAVvsCLV.php

[rotty]

Thanks for reply. I thought all CD/DVD drives were CLV drives. The problem that I have with the internal drive is this.
Say I set the burn speed to 6X, the drive will start at 2X, go about third way through disk then jump tp 4X, last third to 6X.
My external USB drive (CLV) will start at 6X (after about 4secs) and stay at that speed. The spin of the disk in this drive does speed up as disk progresses but burn speed is constant at 6X, unlike the internal drive.

[setarip_old]

I'd suggest that your only concern should be whether the burned DVDs play properly, not which burning methodology a particular burner uses...

[rotty]

They both seem to be ok but the burn time for a disk burned on the internal drive is obviously much longer that you would expect for the burn speed that you set.
It is also a bit worrying the way the speed changes because as it doed the write seems to stop for a few seconds.
Dont want to end up with disks that seem ok that wont play on some machines.
Does anyone else have drives that do this. It seems to be all the latest internal burners.