I know this has been discussed before but do not recall any definite explanation.
Scan 1 below shows the green read speed line increasing and dropping but only up until the 1 gig point.
Scan 2 taken on the very next burn shows just the "normal" speed drop at the start of the burn.
anyone know why 2 burns should be so different. My 1620 always acted like scan 2. The 1640 changes from disk to disk.