Nero CD-DVD Scan : Periodic Speed Drop

It is known that Nero CD-DVD scan of 1620 sometimes experiences periodic spin down and spin up. Most people see it at 12x and 16x scan, but weirdly, at 8x scan only a fraction of people including me reported it.

Today, I found the speed drop disappeared (Compare scan 1 and scan 2 of the same disc, look at the green line). The first scan is done just after its burn, the second scan is done a few minutes ago. As I guessed, the scan is a little bit better without the speed drop; I believe the error is reported higher just after the speed down-up.

Unfortunately, I don’t know what caused such a change. There have been a few events between this and my last scan with spin down-up. One week gap, a few burns, a few flashes, etc. I even flashed it with a disc in it. (Yeah… people do dumb things.)

I always get speed drop when scanning at 8x. At 4x I don’t have the issue.

Theres a way to tell (atleast with my drive) if you going to get those downward spikes, if when you insert the disk the drive take a long time (ie 10+ seconds instead of the normal 2-3) to read the TOC then your going to get this weird reading behaviour. Look like the drive switches to a “slow but sure” reading mode (causing these dips) if it thinks the media is crap.

You also get this behaviour with some crap media if you scan straight after burning, if however you let the disk cool for a few minutes chances are you wont get this behaviour.

Me to. I get the same question
I test the burned disk after 10 min
But sometimes I reset my computer then I test it. The curve is perfect :confused:

Gee, I ALWAYS get these periodic speed up/downs when I test CDs (including pressed…yes, I was bored) I thought they were normal! Haven’t tried scanning DVDs yet, but I guess the result won’t be too pretty either…:*(

I always get them with my 12x burns. I haven’t tried another speed. I use only Fuji +R Yudens. I get no rings and the disks still play fine.
Not too concerned about the thing.