PIF exceeding PIE - do I win? And, the importance of scanning

Blank Media
#1

Hehe, not only is this one of the freakiest scans I’ve ever made, but it also illustrates that people who scan aren’t “media-geeks” -well, not just :wink: - but are safe in the knowledge their discs aren’t accidentally messed up.

Burned these two about a year ago at 4x in a NEC1300A.

They are from the same spindle.

First, I scanned this gem, that had always given my DVD player some trouble:

Now I know why!

And later, this one:

All others from the same spindle that I could locate, showed similar results as the last scan.

Now I’m back to not just testing one in ten discs, but every last one I burn.

#2

Or buy TY’s? :stuck_out_tongue:

My R20’s come out quite poor but my R03’s come out quite nicely. Now only like, using TYG02 and stuffs, je weet toch alles :stuck_out_tongue:

I’m really new to this but even I am impressed with the first scan :smiley:

#3

@Dekoning! : Would be so kind to post a transfer rate test of this disc? I’m curious to see how the high errors impact the 1655’s reading curve… this drive is rather new and I’m interested in how it behaves in this area… :slight_smile: (but maybe it’s off-topic here, so if you post it in the Benq forum please PM me OK? :flower: )

Funny thing, my first backup of Blue Velvet (great movie! :bow: ) was rapidly afflicted with high PIF peaks just like yours! (was one of those G05 discs that gave me and others so many headaches… :Z ) - could it be that Lynch movies do some mambo jambo to the burners? :bigsmile:

#4

I wanted to post it more as a discussion and freaky scan than as an addition to the BenQ forum, so as I understand it, this is the correct place.

The green line is the reading curve. The dip in the beginning (at 138MB) occurs with each and every disc, so discard that one. There was no slowing down, the drive behaved like the disc was perfect. Only when you view the scan, it is revealed to be rather ‘special’.

Especially in the second disc the vertical green lines show that I was multitasking at the time (yeah I know, shouldn’t really do that).

I’m going to flash the firmware with a read-speed unlocked version this weekend, I can let you know what happens when the disc is read at a higher speed if you’d like me to.

PM me to remind me, if necessary :wink:

#5

Sorry but you’re mistaken, the reading curve of a PIE/PIF scan does’nt replace the reading curve of a ransfer rate test! :disagree:

A PIE/PIF test doesn’t “read” the data, it just parses the ECC blocks (simplified explanation), and the drive is not allowed to slowdown by the software! Perturbations can only be caused by background activity… so no actual data reading issue will be reported. The reading curve is reported for convenience.

A transfer rate test is completely different test, it actually reads all the data on the disc, and the drive is then of course allowed to slowdown if it encounters problems reading the disc. Which is the interest of a TRT: does the drive actually read the data easily, without resorting to slowdowns?

Cheers :slight_smile:

#6

My bad; learning all the time… :cool:

Here’s the TRT; at the peak of the PIFs it does show a little dip, but the slowdown is very brief and is not noticeable by ear. I think the drive did very well here.

Hope this tells you what you wanted to know.

#7

Yep, thanks a lot :smiley: - looks like the 1655 is a very good reader…
Cheers :slight_smile:

#8

I have quite a few scans on my 1640 where the max PIF is higher than the max PI, even though it does not seem like something you’d logically see. When it occurs, the PIF levels are usually only slightly higher than max PI levels, similar to your scan.

BTW, RICOHJPN R01 is usually very good media, I doubt you’ll encounter many problems with them.

#9

Maybe the following will help you understand… that’s something I came across only recently, and I’m kinda upset that this very important piece of information is not more widely spread on this board. :frowning:

Take a close look at the two test scans in post #31, take a deep breath, and read Erik’s explanations in post #33…:
http://club.cdfreaks.com/showthread.php?t=120533&page=2&pp=30&highlight=Understanding

#10

I knew that PI + PIF were not combined with Benq drives, that was a given or I’d never see higher PIFs vs. PI in a Benq scan. But I did NOT know that Liteon’s combined PI+PIF for their reported PI levels, seems stupid to me to report them in that manner but it is what it is I guess. :rolleyes: It does explain why PI levels always look ‘agreeable’ with the corresponding PIF levels in Liteon scans. :rolleyes: I would still consider a scan with PIF levels higher than PI levels on the same spot on a disc to be an uncommon occurance with Benq’s, except when PIF levels become VERY elevated and take the place of correctable PI errors. Of course the PIF levels are quite high in the first scan, so a higher level of PIFs than PIs is not a big suprise.

#11

The LiteOn is not stupid in reporting PIE the way it does, it simply reports it according to the ECMA specifications, whereas the BenQ is clearly wrong in not including PIF in the PIE reporting.

Here’s the relevant quote from ECMA-337:

29.2 Data errors
<DIR><DIR><DIR>[font=Verdana]A byte error occurs when one or more bits in a byte have a wrong value, as compared to their original recorded value.

A row of an ECC Block as defined in 13.3 that has at least 1 byte in error constitutes a PI error.

If a row of an ECC Block as defined in 13.3 contains more than 5 erroneous bytes, the row is said to be “PI-uncorrectable”.

</DIR></DIR></DIR>[/font]
Clearly, a row of an ECC block that has more than 5 erroneous bytes (the definition of PI-uncorrectable a.k.a. PIF) must also have at least 1 byte in error (the definition of a PI error a.k.a PIE)!

#12

That is true, the Benq is technically only reporting the PI errors that have not accumulated to PIF levels, not including the PIF level errors in the PIs. But then they are still reporting both PI and PIFs, although you do have to add the PIF levels in as part of the PIs to get a TOTAL of the PI errors. My comment that it was stupid is a bit dumb, I’ve just always considered reported PI levels to be only the errors that have not reached PIF levels. From that, Liteon’s reported PI levels should be considered the ‘total’ PI errors, while a Benq should be considered as ‘non-PIF level’ PI errors’. Now knowing that Benq and Liteon report PIs differently, I personally like having the reported PI levels without the PIF-level PIs, but that is only personal preference. Knowing now how each drive reports PI levels makes it irrelevant though, KNOWING this difference is all that matters. And of course PIF levels are the primary concern, so I don’t put as much attention into the reported PI levels.