Media testing difficulties

vbimport

#1

Here’s a good example of the problems I am running into while doing a DVD media test. I have burnt 2 DVD-Rs (Princo 4x), one on the Sony DRU510 and one on the Plextor 708. I use two identical Lite-On 166 readers with K-Probe, let’s name them 166A
and 166B.

First disc…

Media: Princo DVD-R 4x
Burner: Plextor 708
Reader: Lite-On 166A

Media: Princo DVD-R 4x
Burner: Plextor 708
Reader: Lite-On 166B

Second disc…

Media: Princo DVD-R 4x
Burner: Sony 510A
Reader: Lite-On 166A

Media: Princo DVD-R 4x
Burner: Sony 510A
Reader: Lite-On 166B

Can anyone comment on this? Apparently it’s not just the writer, but also the reader even if it’s the same model. Yes, both DVDs were written and read with the same speed.


#2

The only thing we know for sure is that lower is better. Do the discs all function correctly?
The 166 is locked at 8x CAV reading, which is responsible for the large spike of errors near the end. All I can say is to use whatever media and burn speed that gives you the lowest error rates. Also consider DVD+, the error rates seem to be a bit lower.


#3

DVD+R is up next. But the thing that strikes me most is that testing the very same DVD-R in two identical systems with two identical Lite-On 166 readers gives to very different results… how is that possible? I’d almost say one of the drives would be broken…


#4

Well, there’s no such thing as 2 identical drives or 2 identical discs, or even 2 identical scans of the same disc in the same drive.
The 166 is at best, unpredictable, partly due to the 8x read speed. All you can do is test everything untill you get a feel for the way the drives behave. I think that media is somewhat inconsistant too.
If you figure anything out, be sure to let us know! :wink:

And welcome to the forum!!!


#5

Thanks. I’m about to test about 40 different brands (20 +, 20 -) so all the input is welcome. I guess I can already conclude that it is impossible to give a concrete answer on the question “is media X good or bad”. The only thing you can say is, if burnt and read on the same devices, “media X performs better than media Y”.

So I guess what I will do is burn two DVDs per brand. One on the Plextor and one on the Sony. Then compare the DVDs to the ones burnt on the same device (and naturally, read it with the same device). That way I can at least draw some conclusion on which media perform better or worse than average. :slight_smile:


#6

Well, you will certainly know what works for the given drives. Be sure your firmware is up to date.


#7

Just a small test: Why not try to swap the DVD-ROMs around? Just to see if the computer could make the result different…

It’s probably the drive that is causing it but it would still have been interesting to see…