I'm using Nero DiscSpeed to check a bunch of DVDs from a box set (one was broken and the seller offered to replace it and any other broken ones) and
What is it about DVDs that some of them can be read at up to 8x speed and others no more than 1.5x on early sectors and 3x on late ones?
like what is the physical difference between the discs that makes the drive (or driver?) limit the speed to 3x for some and not others