New to Quality Scanning with 3520a

vbimport

#1

hey everybody, i recently updated the firmware on my 3520a to the official 3.04 and immediately wanted to do quality tests on the stuff i backed up earlier. So after learnign about kprobe and finally realizing it woudln’t work on my NEC, i got into CD-DVD Speed and got the latest (3.80) version and started runnin tests.
This is the latest one i got and i have a couple questions.
The first is about the speed. The DVD-R is 8x, shoud i leave that testing speed on maximum? the same speed as the cd? lower? any rule?
Second, if i were to lower that speed, would i get better results?
Third, he light blue PI Errors scan section that i circled in red seems worse than the other parts of the scan. Yet no major section is over the 280 limit i found to be a good guide in this post: http://forum.cdfreaks.com/showthread.php?t=80545. Same for the PIF scan, nothing over 32.
So overall, is this a good scan? Did i do anything wrong? Anything else i should know?
Thx in advance!
David


#2

So far 5X scan speed seems to give the most sensible results. Max is certainly to fast.


#3

So i will rescan with 5x soon, either way, would that scan be considered bad, good, average, what else?
What abotu that circled section, is it that bad?


#4

Yes, that is bad. You want it all to be low.


#5

how low?


#6

Read up on testing here. It is not a subject that lends itself to a short answer.

http://club.cdfreaks.com/forumdisplay.php?f=96


#7

I’ve read ALL of the stickies. But now that i know the “theory” i wanna know how it applies in real life. And im using this scan as an example. So far i learned to scan at 5x. What else can you guys tell me? Is this scan (even though it’s at maximum) good or bad? If bad, how bad? If it should be lower, how low?
Come on guys :slight_smile:


#8

Reality is it is just fine. DVD movies spin at 1x, DVD-data can spin upto 16x. As long as you don’t have any POF, you are fine. PIE/PIF are RECOVERABLE errors so no matter how many you have you can recover.
I always test at MAX and just ignore the last quarter of the disk, if the first 3/4 are OK, then the rest is likely ok also… But then again, I don’t spend endless days on this forum and do not waste dozens of blanks on test burns…


#9

By ignoring the end of the disc, you ignore the most likely part a disc will fail. countless 1000’s of tests have proved this.


#10

I too have had a hard time learning the finer points of interpreting CD / DVD Speed scan’s. All I have been able to find is:
PIF < 16
PIE < 280
POF = 0
Jitter < 12%
Scan at 5x for best results
Someone else posted a scan in a different thread that Dee said had too many errors concentrated in one part of a disc, although the complete scan still fell within normal / acceptable paramaters. So, that must also be an aspect that should be taken into consideration when reviewing a scan.
Wouldn’t it be possible for a “CD / DVD Speed FAQ / Instructions” document to be created by one of the more experienced forum members?
That would certainly be useful in my opinion.

Thanks,

Wamozart


#11

Ok, I just scanned this more or less “poor” quality media. What does it show me? It is “bad” in the beginning and “bad” in the end? But is it a “bad” disk? No! Because it will work in any player I stick it in (well, except my old dvd-player which doesn’t recognize dvd-r and 1.ud and 1.ue have brocken bitsetting mode)

So my point is, that unless your disk has POFs then it is just fine. Now if someone can show me some correllation between PIE/PIF and the life of the disk (will it still be readable 3/4 years from now), then we’ll talk.



#12

PIF < 16 … if scanned at 8 ECC… at 1 ECC… PIF < 4

PIE < 280 … if scanned at 8 ECC or scan converted to 8ECC (mostly)

POF = 0 … always true… if the drive supports POF scanning (Nec doesn’t)

Jitter < 12% … this is only true for BenQ… but very little burners support Jitter scanning anyway… Nec doesn’t.

Scan at 5x for best results … probably true. =)

However this are only the specs… most drives will still read the disc even if you get higher values than those… it may also happend that you get good low values and the disc is unreadable.


#13

Of course there is a correllation… also a common sense tells you that there is a correllation. Discs will deteriorate over time… however the deterioration speed is different from disc to disc. However disc deterioration can’t be mesured right after a burn… you can measure it using multiple quality checks in different times. However if we have a disc that has the same deterioration speed… one with a lot of correctable error and another with a few correctable errors… the one with a lot will always become unreadable first… so the one with a few correctable errors will last longer.
Why so… well the second one had more “breathing room” for correcting the errors as the first one that had a little “breathing room” because most correction had to be done because of a poor burning.

Also if a disc has little errors after a burn… you can say the quality is good but this is more like a burner - disc correlation. So a disc that has little errors also has a greater chanse of “surviving” disc deterioration longer than other discs and also a greater chance not to cause reading problems in other devices. You can still have POF 0 and the disc is causing reading problems because of too high jitter for example.


#14

Where is the proof that PIE/PIF errors are related to the physical deterioration of the media layer? As far as I can tell PIE/PIF are caused by the laser (that’s why different quality lasers in different burners are responsible for burners being qualified as good or bad). Furthermore, different firmwares will control the laser a little differently allowing it to write (hopefully) a little better to the same disk. So “cheap” media will burn better on a good burner than on a “cheap” burner. So let’s assume that PIE/PIFs result after of a burn, and the amount of PIE/PIFs is a combination of quality of the buner/media.

Now assuming that, do we also assume that physical deterioration of the disk is the same thing as just too many PIE/PIFs? And that overtime PIE/PIFs just sponteneously appear on the disk? And that if it is a good disk, then it has “room to spare” for PIE/PIFs? I don’t buy it!!!
Has someone actually done a long term test like this? It’s the same thing with UFOs, until I see some proof, I won’t buy it!!


#15

There is no proof… I already told you disc quality test is not a measure of disc deterioration. So you can’t say a disc with little errors will last longer than a disc with a lot errors… because you don’t know the deterioration rate. I said only that disc low error disc with the same deterioration rate will last longer. Obvously you don’t understand what it means that 2 disc have the same deterioration rate… this means that overtime the same amout of errors will spontaneously be created because of deterioration. Also PI/PIF aren’t only casued by laser during writing… they are casued by laser not being able to read back the data propely. PI and PO are additional data used for error correction on the disc… so PI is used when data isn’t read back properly and which can be detected by the EDC code… then if the writer can correct the error using PI data… then we call this PIE… if not then we call this PIF. Then PO has his chance to correct the error. If he succeded then we call this POE if not then we call this a POF… and the data can’t be read back. So the drive tries again (and again and again… until it gives up). As said errors will always increase through time because of deterioration… now I will hopefully give you a easy to understand example:

let say 1 error is 1 PIE, 100 PIE are 1 PIF, 100 PIF are 1 POF.
We have 2 disc…

after burn
disc 1 has 10: 10 PIE, 0 PIF, 0 POF
disc 2 has 9,000: 0 PIE, 90 PIF, 0 POF

after for example 6 months 1,000 errors emerge because of disc deterioration
disc 1 has 1,010 errors: 10 PIE, 10 PIF, 0 POF
disc 2 has 10,000 errors: 0 PIE, 0 PIF, 1 POF

So after 6 months disc 1 is readable without unrecovered errors… but disc 2 has 1 unrecovered error and can’t be read back perfectly.

Now this prooves in theory that I’m right.


#16

I have seen the deterioration effect with CDs, so it makes sense that this can be expected with DVDs too.

As a disc is used, it probably gains a bunch of scratches. You can also consider this to be physical deterioration.

A few weeks ago, I wrote a line using a permanent marker on the lower side of one of my test DVDs. There was a definite increase in errors (especially PIFs if I remember correctly). I think the effect of the permanent marker can be compared to the effect of scratches.


#17

bertrik: Even without a scratch… discs can and do deteriorate. Things like sunlight, humidity, temperature or with other words environment factors cause the disc dye to deteriorate. DVD aren’t the perfect data storage media that everybody think it is. If you burn something on it won’t last forever… not even 100 years… maybe not even 10 years… even if you seal the disc in a dark room and don’t use it for this period of time.


#18

lol, im so lost.
So is this scan of mine ok?
What should i be looking at specifically for a good/bad scan, just the 280/16 rule? Can you elaborate a little on the ECC part, im not sure i got that from the readings and your post…
Can we know at all how long a dvd is gonna last from teh time it’s scanned?
Thx a lot guys for offering so much information, i really want to learn :smiley:


#19

In the beginning I put stickers on the DVD’s and after one year they are not readable anymore… but that’s a whole other story.


#20

Are we talking about the same thing? Do you mean of DVD deterioration as it is described in these couple articles?


http://www.andraste.org/discfault/discfault.htm

Are you saying that PIE/PIF/POF is the same thing as blotches appearing on DVDs that are visible using a microscope? So if take a microscope and look at TY002 with excellent quality burn and el-cheapo CMS with “poor” quality burn I will PHYSICALLY be able to see the defects on the cheaper disk?

Hmm, where is that electron microscope of mine…