Who do I trust?

vbimport

#1

On one hand, my CD-DVD Speed quality test gives me an average of 7,21 PIF, with 11 PO’s. I see quite a bit of red and purple in the first GB of the DVD, then it drops back to green. CD-DVD’s quality score is zero.

On the other hand, I have a perfect reading line on the CD-DVD Transfer test. And all the files were copied correctly off the DVD, with no slowdowns that I could detect.

So which test is lying to me? I’m running it off a Benq 1640, with the latest firmware.


#2

Could you post your quality scan here, please?


#3

and


#4

Perhaps your drive doesn’t like to scan at 8x P-CAV.
The worst PIE/PIF seems to be at the beginning of the disc in that scan.

Could you please also try to scan at 8x (CAV) and post the result?


#5

In any case, that’s a G05 that’s going to fail, and soon.


#6

I’ll post the image in a few moments, but the results are the same. Lots of problems until I reach 1GB, then it smooths out.

So where do I put my trust, on the Quality Test or on the Transfer Test?


#7

I agree with CDan, that disc is going to give you problems!
It might already be unreadable or unplayable in some drives, and there’s great risk of it becoming unreadable in the BenQ soon.

Believing the Read Transfer test and believing the Disc Quality scan is not so much a question of either or. It’s better to think of it in this way: Each of those tests tell you only a part of the whole story, and even together they don’t tell the full story.

The only safe course of action IMO, is that if either of the two test types show a problem, then the disc has bad quality. A perfect Read Transfer test cannot compensate for a poor Quality Scan, and a beautiful Quality Scan canot compensate for a poor Read Transfer test!

The only exception is if the drive is known to be an unreliable reader or an unreliable scanner.


#8

That’s a very ‘borderline’ disc and even though it has a perfect TRT, all is far from well with your disc. This is a perfect example of why just running a TRT is misleading. If the error spike was near the edge, there would almost certainly be at least some sort of speed dip from the higher speed near the edge.

Both tests are probably accurate, you just have to understand their limitations.


#9

Both [B]DrageMester [/B]and [B]Scoobiedoobie [/B]comments are wise comments. :cool: (as usual… :bigsmile: )

Last year, I had countless customer complaints about some of my duplication ‘lines’. The discs were all failing after 3 to 6 months. It was easy to trace it down to the use of Ritek G05 discs (which incidentally brought me to this forum :wink: ).

What I noticed with Ritek -R discs, G04 and G05, is that they keep on being readable despite being heavily degraded. What I mean is you can see an ugly scan, which would indicate a coaster with different MIDs, and the Ritek disc is still readable. When it fails, it generally fails suddenly, when errors reach some unknown “treshold”. At least that’s the way I see it. And I don’t like it, these discs are ‘time bombs’. :Z

Maybe it has something to do with the excellent reflectivity of G04 and G05 discs, which makes them very compatible with most readers. But this comes with a price, one that you don’t want to pay: scary unstability, meaning short life and data loss hazard.

I’m not suprised that your disc shows a good reading curve despite the awful scan. But considering both the scan and the recent history with Ritek G05 discs, this disc WILL fail sooner or later, probably in a matter of weeks.

Sorry for the bad news. :frowning:


#10

Hmm, at least mine RiTEKG04’s are not any “time bombs”. They have been playing well for the last 2½ years and I’m sure they will play fine many more years. :smiley:
Go figure…

RiTEKG04 4x rated (Traxdata H4-6L19307129329B00) burned with Lite-On 411S fw FS0F, burning software RecordNow Max 4.5 (Stomp)
Burned: 2004-02-06.

Link to scan right after burn above date. Attaching rescans and TRT performed today.

[I]pic1.[/I] Scan @8x speed CAV BenQ DW1640
[I]pic2.[/I] Scan @8x speed P-CAV BenQ DW1640
[I]pic3.[/I] Scan @4x speed Litey 1693 KProbe
[I]pic4 [/I]Transfer Rate Test @16x speed NEC ND-3500
.






#11

I have some that are not degrading either. I have had lots of G04 failing and it’s probably because most of these were bought in 2005: I have been reading posts from [B]Francksoy [/B]and [B]chas0039[/B] that the problems with Ritek -R production started in the second part of 2004. I know that many are happy with their old G04 discs. :iagree: It’s their good reputation that had me buying so much in the first place! :doh:

My warning about ‘time bombs’ is because there are still some G04 available on the shelves, and these are most probably not from old production and are then to be avoided, just like G05.


#12

Can’t find my RiTEKG05 media right now (not at home) SantaKlaus. But from what I recall theirs longevity also depends on batch and production time.

While you are out warning members about time bombs, why not also mention all other crap media you seem to know about…
I never had any problems with crappy media except for Princo 1-4x that failed on me within 6 months. :stuck_out_tongue:


#13

So ultimately both are reliable and unreliable. If one tells you the disk’s not so hot, then the disk’s not so hot.

But the quality test usually paints a far more accurate picture than the transfer test, and I’ve never seen a DVD with a crappy transfer test + near perfect quality test. So I guess I’ll put my faith on the quality one (but still keep an eye on the transfer test).

Thanks for the hand guys :slight_smile:


#14

If you look at this thread, that will change.
I have also had some coasters with good PIE/PIF scans.

Ignore Read Transfer tests or other actual reading tests at your own peril!


#15

I’ll second that, big time. :iagree:
PIE/PIF scans are given far too much credit. They’re extremely useful for several purposes, and I couldn’t live without them, but they give no warantee that the data is intact, or even that the disc is actually readable without major errors.
A good looking scans lowers the probability that you have a coaster, but doesn’t guarantee it. [B]DrageMester[/B] has shown several examples of this. I have too, but can’t find the links again, sorry… :bigsmile:


#16

Here’s one of mine:

http://club.cdfreaks.com/showthread.php?p=1339958#post1339958


#17

[B]DrageMester:[/B], Is this experience of yours that some discs with good PIE/PIF scans but problematic TRT relates solely to burns done on a NEC drive and read by BenQ 1655?

Or have you found other combinations which exhibit this behaviour as the example [B]Francksoy[/B] also mentions is of exactly the same combination. Would be useful to know if other BenQ drives exhibit the same behaviour or is this just an unlucky combination.


#18

This exact problem is something I have only experienced with DVDs burned in a NEC ND-4551A and read and scanned in a BenQ DW1655.

I have had DVDs burned in a NEC 4551 which had slowdown problems in a LiteOn 1635S drive without showing problems in my other drives (not counting the BenQ and LiteOn 165P6S which I didn’t have at the time), and which had good PIE/PIF scans. See this thread. The DVDs were readable but some had “damaged” sectors in ScanDisc on the LiteOn 1635S.

I have had one or two DVDs burned in a LiteOn 1635S that had unreadable sectors in both my LiteOn drives and my BenQ drives, but which read flawlessly in my other drives. I’m not sure how the PIE/PIF scans were because I didn’t save the scans, but I think I might still have the disc(s) so I guess I could perform the scans again.

I have also had DVD burned in my Matshita UJ-840S laptop drive which had unreadable sectors and POF when read/scanned in my BenQ and the disc didn’t show any problems in other drives.

So it’s really a mixed bag, but in general the BenQ is the pickiest reader of all my drives and sometimes it doesn’t even show any POF or even PIF for sectors in cannot read.

The LiteOn drives are generally excellent readers, but there are some discs where they are pickier than most other drives (except the BenQ).

The NEC 4551 is the worst burner, because it can produce discs that have transfer slowdowns in LiteOn drives and undreadable sectors in BenQ drives.

Are you confused yet?

The conclusions that can be made from all this are:

[ul]
[li]A good PIE/PIF scan in a LiteOn or BenQ drive doesn’t guarantee readability in the same drive.[/li][li]Some discs are readable in some drives and not in other drives, and this cannot always be detected by PIE/PIF scans in the drives that don’t experience the reading problems.[/li][li]If you only use one drive for testing whether your DVDs can be read, you might be in for a nasty surprise when you try to read the disc in another drive of a different brand.[/li][/ul]


#19

Thanks for the summary of compatability issues. I’ve never come across discs which behave in this manner (Good PIE/PIF but readability problems) so it would seem fairly rare.

It would seem to me that the burner is the source of such non-compatible discs and the BenQ/Lite-ON happen to be susceptible to whatever issues those discs have.

If you have the chance to test some of those discs on your BenQ 1620, would be most useful to help identify wether all BenQs suffer from the problem.

If only a relatively reliable low level scanner was available to troubleshoot such things for consumers. :frowning: (CATS/DaTARIUS is too expensive)


#20

I don’t have a BenQ DW1620 myself, it belongs to my dad so I only have occassional access to it.

Others with access to NEC 3550/3551/4550/4551 burners or the newer 4570/4571 burners and which also have a BenQ 1620/1625/1640/1650/1655 could see for themselves, whether they sometimes have problems for discs burned at 16x or 12x in a NEC drive and read in a BenQ drive.