Disc scanning question?

vbimport

#1

Ok, I would like to know what is a more important factor, PIE & PIF scanning or speed transfer rate/test? I have seen the same disc show high PIE/PIF values but super smooth graph to 16x on the speed test. Also seen super low PIE (ie 10 Max) and low PIF (ie 2 Max) and very big drop off at the end of he disc on a speed test (ie down to 6x).
Which is the better indication to a good quality disc?
Thx


#2

I asked the very same question and the answer was the transfer speed test :slight_smile:

I’ll have a dig at the thread for you.

Edit: found it!

I asked:

Just as a side, if your BenQ 1640 reports excellent quality scores but horrific transfer speed curves, then does that mean the disc is unreadible and will likely to fail?

Which one’s worse: appalling quality score (very high PIE/PIF), or zig-zaggy transfer speed curves?

and in reply:

Transfer test is the most important. A scan reads at 8x on the Benq. Transfer tests a read to 16x. Ideally a smooth curve to 16x means a good burn even if the scan does not look that hot. What counts most is ‘does the disc read properly in a multitude of readers?’. A scan ‘may’ give some indication of lifespan or potential future problems (But only very generally).

Sometimes we attach too much importance to scans. BTW how about scanning at max speed and see what it says towards the end of the scan? Might give some more info about that read error near the end of the transfer test perhaps.

Hope that answers your question.


#3

Completing a transfer rate test does not tell you anything about burn quality. It only tells you that the reading drive is able to read the disc at full speed. Both tests are just different pieces of the puzzle. Neither is “better”, and neither should be relied on by itself if you have concerns about quality.


#4

From what i remember the transfer curves usually mess up because of high jitter even if quality scores are good.


#5

I’ll have to disagree somewhat.

If a test can’t tell you anything about burn quality it would be utterly pointless!

A Read Transfer test tells you something about burn quality. PIE/PIF scanning also tells you something about burn quality. A Beta/Jitter graph also tells you something about burn quality. Scanning PIE/PIF at more than one reading speed also tells you something about burn quality. Scanning in more than one drive also tells you something about burn quality.

All the something’s add up to a better idea about burn quality than any piece does on it’s own, but they still don’t add up to telling you everything about the burn quality.

IMHO if a Read Transfer test fails in any drive I consider the DVD a coaster regardless of PIE and PIF levels. And I don’t mean fails as in “looks ugly” but fails as in “cannot read the disc all the way through”. (Yes, I know that the disc may still be readable if read in a normal way.)


#6

Not true at all.

Transfer rate test tells you only that the disc can be read at x speed in THAT drive. You can make assumptions about burn quality based on that, but you will sometimes be wrong. In other words, a 8x or even 16x transfer rate test can be successful even with relatively high PIE and to some degree high PIF.
It’s also true that a high speed transfer rate test may slow down for a number of reasons that are not related to burn quality. It really depends on the testing drive and it’s relative compatability with the media in question. Some media will never read at 16x in some drives no matter how well it’s burned.

The same can also be said of PI/PIF scans, they only indirectly tell you about burn quality. But it is very unlikely that you will see low PI/PIF in the case of low burn quality. It’s equally unlikey that you will see high PI/PIF in the case of high burn quality.

Where these 2 tests might disagree is on a disc that is of marginal quality, as many are. It might scan with higher error rates but still complete the TRT at full speed. (see above). That does not mean the disc is “OK”. And in that case the TRT has failed to tell anything about burn quality.

If I had to choose one or the other test as my only means of checking burns, there’s no question it would be error scanning. I have yet to see a poor quality disc not be picked up with a scan. The same cannot be said of the transfer rate test. Neither test is more “important” or more accurate in any sense, they are very different. I can see very little purpose in doing both tests on one disc though, and any disc that “fails” my error scan is going in the trash without further investigation.

Transfer rate tests have their main value for those people who do not have a good scanning drive.


#7

Actually it’s completely true.

Waving a DVD through the air listening to what sound it makes would tell you absolutely nothing about burn quality and would thus be utterly pointless.

Doing any of the tests listed above, including a Read Transfer test, will not tell you everything about quality but they will tell you something. This is exactly what you are arguing yourself - except that you then conclude that the tests don’t tell anything.

Please make up your mind! :bigsmile:

Yes, so it does tell you something - namely that the disc can actually be read, which in fact is the only capability of the disc that is absolutely ESSENTIAL. It does not however tell you whether the disc can be read in some other random drive.

Perhaps you’re right, I haven’t seen this myself. Even if it is the media itself and not the burn that makes it hard to read, I would consider that to be VERY relevant information - wouldn’t you?

No, the TRT has failed to tell you everything about burn quality.

Are we having a disagreement over the meaning of the words “nothing”, “something”, “anything” and “everything” here?

In my experience the Read Transfer Test on one of my drives (NEC 3500) is the single best predictor of whether a disc can be read back in any of a handful drives, and PIE/PIF/POE/Jitter/Beta scanning is not nearly as good at predicting this.

Your experience is obviously different from mine, and it might even be more extensive, but don’t be too quick in dismissing experience that differs from your own.

Yes, but they can also be essential for people who DO have a good scanning drive - provided that the Read Transfer test can be done on a drive that is a reliable predictor, as e.g. my NEC 3500 drive is.

No disc I have ever tested in my NEC drive that could be read at full speed (16x) have shown any problem in other drives. All discs that have been difficult or impossible to read in any drive have also shown this in a Read Transfer test on my NEC 3500 drive. Some of these discs do not show an excessive amount of PIE/PIF when scanned in my Plextor PX-712A drive, and I know from experience that my PX-712 specimen is not a particularly good reader (it shows roughly 50% to 200% higher PIE/PIF total on the same exact disc when compared to a friend’s PX-712).

If I were to perform only a single test, given my selection of drives and their capability, it would be a Read Transfer test at maximum speed on my NEC 3500. All the Q-Scan tests on my Plextor PX-712A combined simply don’t add up to being as good a predictor for reading problems in other drives!