Read Transfer Rate curve. What could be causing this?

For no apparent reason when I attempt to burn a DVD I keep getting the following results when I use Nero CD/DVD Speed to run a Tranfer Rate test.


I have used three brands of discs, all from reliable batches, including some ultra reliable TYG02 I have never had any coasters with. All burned at x4 speed. As I always use. The same thing happens on every burn. The curve gets to anywhere between 3.0 and 3.5gb and then levels off as if it has hit a ceiling in cannot surpass. No spikes, almost like it’s being ‘throttled’.

I’m have been using an LG 4163B DVD drive. I have also replaced it with a newer, unused, LG 4167B and the result is still the same.

I have now burned several discs with every piece of non-essential hardware and software disabled, monitored CPU and pagefile usage for the entire duration of the burn (without issue), and still I keep getting this problem. Always approximately around the same region of the burn.

There were no buffer underuns in the burn process using Nero and all discs verify perfectly, albeit never reaching the read speeds they should be past the 3.0-3.5gb mark. The Nero burn log did not exhibit any errors that would indicate there was a problem.

Any ideas what could be causing this ?

Thanks.

First of all those scans look great, nearly perfect.

What you are seeing is the effect of P-CAV (Partial Constant Angular Velocity) strategy that is determined by your burn speed and drive.

Nero and all discs verify perfectly, albeit never reaching the read speeds they should be past the 3.0-3.5gb mark.

I doubt it has anything to do with the 3GB mark, it’s about your drive switching from CAV to CLV (Constant[B] Linear [/B]Velocity) when the maximum speed is reached. This is what P-CAV is.

Things may change if you burn your discs at their rated 8X speed or use 16X discs. I see no reason to go slower with the TYG02s.

That said your scans are fine. If you search the web you’ll see that when P-CAV is used that’s the kind of curve you’ll see.

Here’s a CAV:

Here’s a P-CAV:

Note there is newer FW for your 4167.