Here is Why You Don't Compare Scans

This comes up a lot so I figured I would put some of my burners to work and do some scan comparisons of the same disc scanned on different drives. The disc is a TYG01 burned at 8X on an NEC 3520 with 1.UF firmware. I pushed it to 8X so I could get some errors to work with. The first scan is done on a Liteon 832S with Kprobe at 4X. This is the standard as far as I am concerned. I know there are problems with this assumption, but this is what we have to work with and we have to start somewhere.

The second scan is done on the NEC 3520 at 8X. This is wrong for a number of reasons but a lot of people do so nonetheless, and the point of this is to show the problems when you make slight errors or try to compare different drives and software.

The last scan is done on an AOpen 1648 AAP at 4X. Scanning on a ROM drive is supposed to work if you just multiply the error reading on the PIE by either 8 or 32 or some other magic number. I cannot seem to find the magic number here and I don’t think anyone else can either.

I am sorry I couldn’t add a BenQ scan but as you may know my BenQ is spending more time at the RMA center than in my computer. I also thought I had read that the Pioneer 109 could do scanning now but it wouldn’t cooperate. I would have liked to add a scan from a Liteon 1693 so I could see if there is a difference between older and newer Liteons but Newegg has not dropped the price to $45 for me so I am out of luck.

For these scans, the only reliable thing was that the PIF s were fairly low for all.

I posted this in the drive section because, even though it has to do with media testing, it is more useful as a measure of drive variation.

Chas, thanks a ton for this data on not comparing scans from different units. DrageMaster succeeded in getting one person in the Plextor Quality Scans thread to use the same burner for the scans (he used two different Liteons), saying it in words rather than scans. I think I’ll post the link over there. :wink:

Otherwise, there’s a HUGE difference in PIE and still a fairly big difference in PIF. That would confuse the sanest person, I think. :rolleyes:

BTW, chas, I have a DVR-108. I can’t say anything about the 109, but I can use DVDInfoPro with the 108, but only PI/PO, no jitter, no failures… All I can say is that the 108 is definitely a sorry, inconsistent drive for scanning burns. Also, although DVDInfoPro is like Nero CDSpeed, with the limited scan reporting, it was confusing and I could not compare the results from the Pioneer with anything else meaningfully.

thanks again for that great explanation with the graphs to back it up! (thumbs up)

That’s what it was I read, scanning with DVDInfo. Thanks for jogging my memory.

And imagine the amount of confusion one could experience when scanning various media burnt in various with various firmware releases with various firmware patches with various speed differences set for each MID and you have scanning drives of:

Lite-On 811 Lite-On 851 Lite-On 832 Lite-On 1213 Lite-On 1633 Lite-On 1673… Each model will report differently and sometimes different firmware will affect it differently.

Lite-On 832/1213/1613/1653/1673/1693 are all good for PIE and PIF scanning and they tend to report low numbers in both K’s Probe and Nero CD Speed. The graphs look good. BenQ drives I feel are more “dynamic” for scanning. Plextor? Not user-friendly because of complicated use and high cost.

So Chas what are you saying? The old flop it into your DVD palyer and see if it works is not a bad test after all! LOL

I’m saying Liteons were made to scan. Stick with them.

As far as compatability is concerned, that doesn’t make any sense, chas…

We know that scanning is really a test of how drives read disks. Unless all standalones use Liteon chips, your statement is bogus.

IMHO, a disk that scans well across multiple drives is better than one that can pass on only one. You can’t just throw out perfectly good data because you don’t agree with it. That’s false security.

My BenQ burned TYG02’s look good on the BenQ, but crappy on the Liteon. Same media burned with LG/NEC looks great on both…I no longer burn my TY -R media on my BenQ, because I want good scans across the board.

I would feel better giving my customers a disk that had 92 quality scans in three separate drives than a disk that gave one 99 and two 60 scores any day.

Yes, I think Hawseman has a good point here.

Scanning is NOT a competition where you win if you get the lowest PIE/PIF numbers.

Scanning is done to predict how well a disc will read in any random drive you put the disc in. Since it’s not possible to test a disc in all the drives in the world, the compromise is to scan in a few drives of representative quality and then try to deduce something from that. This means that it is actually a DISADVANTAGE to scan discs in a good reader, and LiteOn drives are usually good readers!

My experience is that my NEC ND-3500AG drive is not a very good reader, which gives me the advantage that any discs that produces a smooth Read Transfer scan in that drive will read perfectly in most other drives!

All discs that I have had problems reading in any drive has also shown difficulties in my NEC drive, whereas I can sometimes read a disc perfectly in my Plextor drive even though it fails completely in some other drives. This means that my NEC drive is actually a BETTER predictor than my Plextor drive!!!

If 3 different drives showed the same Nero CDSpeed quality score (ie max PIF value) of 92% and similar PIE values then the scans from those drives are comparable!

I found that there are some MIDs that show comparable scans on different drives and other MIDs would just give completely different result. So the bottom line is, be careful if you are trying to compare scans from different drives, and it’s better not to. :slight_smile:

There are some of my illustrations in point.

DVD+R TDK 8x (TDK002), 16x burned by Benq 1620.

  1. Benq 1620 scan, Nero CD-DVD Speed, 8x CAV, PI/PIF 8ECC.
    2-3. Plextor 712 scan, PlexTools, 2x CLV, PI 8ECC, PIF 1 ECC.
  2. NEC 3540 scan, Nero CD-DVD Speed, 5x CAV, PI/PIF 8ECC.

Benq and Plextor scans are near the same, NEC scan is numerically total different.
NEC PI level exceeds theoretical PI maximum for 8ECC - 1664.

DVD+R 8x Fuji (RICOHJPN R02), burned 12x by Plextor 712.

  1. Benq 1620 scan, Nero CD-DVD Speed, 8x CAV, PI/PIF 8ECC.
    2-3. Plextor 712 scan, PlexTools, 2x CLV, PI 8ECC, PIF 1 ECC.
  2. NEC 3540 scan, Nero CD-DVD Speed, 5x CAV, PI/PIF 8ECC.
  3. DVD-ROM Lite-On 167T scan, Nero CD-DVD Speed, 8x CAV, PI 8ECC, PIF 1 ECC.

There are different results, both numerically and in a qualitative sense.
Benq result is too optimistic.
NEC 3540 and Lite-On 167T scans are similar, strange as it may seem.

In the first one of those, they all agree on the trend (poor at the end) - the Benq held it together better, but that rise in jitter seems to be a prediction of difficulty.

The second one, very little agreement, other than Liteon & NEC

Right, GeoN…

My findings are the same in regards to the BenQ. It must be an exceptional reader.

As much as Maxell 8x scans look mediocre with PIF totals, the scans are very consistent between most scanning drives as burned by all my drives. This, in itself, is important for overall compatibility, and a good test of media quality that is much too often overlooked and clouded by that selective ‘99’ post.

Now that almost all new drives can perform scanning functions…I think it’s important to see how all these drives view my burns.

I agree that analyzing different scans to a gnat’s azz is not recommended, but ignoring scans from other drives is just plain ridiculous. If you believe in scanning, you just can’t “pretend” that other scans are bogus. They are real world results. Don’t claim that quality scanning is an important tool, then hide unfavorable data.

My comments on Maxell 8x -R media above are legit. I wasn’t very impressed with the total amount of PIF’s from my burns…BUT, now that I’ve seen it burned in all my drives and scanned with consistent results in both the BenQ and Liteon, I’d rate the media very high for compatability. It’s great that BenQ burns and scans TYG02 media fine…but my litey tells me the BenQ burns it like crap. That kind of comparison information is important and shouldn’t be ignored.

That’s my 2 cents…

<ps.> Not to pick on the BenQ…it’s one kickarse +R burner. I have no better burner for +R media (including Maxell002, MCC and Yuden).

This might make my point:

5 different drives, 2 different scanning drives…not same disks (all look the same anyway). Maxell RG03 (MIJ 8x -R) both branded and printable mixed - doesn’t matter. It’s cookie cutter. Scanned on BenQ & Liteon 451S (was @832S) (CDSpeed/Kprobe).

1st - me ole’ Pioneer A06 f/w 108 stock
2nd - NEC 2500 f/w 10A stock
3rd - NEC 3500 f/w 2.19 stock
4th - LG 4163 f/w 104 (maybe 103) stock
5th - BenQ 1620 f/w B7V9 read speed adjusted (else, stock)


NEC 2500 -

NEC 3500 -

LG 4163B -

BenQ 1620 -

Can this consistency stress my point enough? Never had any issues with this media in any of my 5 standalones…got to be some kudo’s for that.

NOTE: sorry about the missing MID on the 3500 CDSpeed scan…that’s a known issue with 3500 burned media scanning on a BenQ…usually re-inserting or re-booting fixes that.

We know that scanning is really a test of how drives read disks.

Not so, unfortunately. Perhaps you mis-used the term “read” here. “Reading” is what goes on in transfer rate tests and file tests. Scanning forces a drive to lock speed and never re-read to correct, so it eliminates error correction in the reading process. The disc is being read, but the data is not.

There are a number of reasons to “eliminate” some drives as error scanners, mostly the way they report errors and what they actually DO report as PI/PIF. In this regard, they are all different in some ways, and IMHO some of them are not usefull for my own purposes. Most, if not all, of the arguments offered for one drive over another as a scanner are just rationalizations in an attempt to justify using one’s favorite drive.

Personally, I will not use a drive for scanning that reports PIF in anything other than 1ECC blocks. There’s just no reason to accept 8 ECC or higher reporting when 1 ECC is available. Again, my own preference.

It’s always been true that comparing scans from different drives is foolish, but that is equally true whether they are 2 different drives or even 2 drives of the same model.

People never seem to get a grip on the idea that the purpose of scanning is not to compare drives, but to compare DISCS.

If it’s reading parity bits, it’s reading…how it reads parity bits should be a direct correlation to how it reads data. How it perceives disks is probably how standalones may perceive it (since most drives are manufactured by the same companies). If a manufacturer cannot get their drives to read parity correctly, how the hell are they going to get the drive to read data correctly? Especially since parity correction is a required part of the normal data reading process.

What you’ve just said is scanning is senseless, why do you still do it? Myself, I don’t believe that it is. In my above case, I really think that Maxell has put forth an effort to continue it’s high compatability record with it’s 8x media at the cost of PIF’s.

Don’t be a deleted…You didn’t necessarily buy your LG and NEC’s because of the price. You liked the way the scans looked. That is scanning to compare to drives in my opinion.

You didn’t necessarily buy your LG and NEC’s because of the price. You liked the way the scans looked

Don’t tell me why I buy this drive or that one, cause you don’t have a clue.

That’s scanning to compare drives and you know it.

Nor do you have a clue as to why or how I use scans, or what I know or don’t know.

Calling people names just serves to discredit your ideas and adds nothing to the discussion.

Alright, I apologize for dropping names, that was a little un-called for…It’s edited out. I’m usually not this testy…

I just don’t agree…Many people base their purchases on the findings here…I’m one of those, and believe you are too. It’s not a bad thing, just “discredits” your post about scanning for drive comparison.

I also know you are very knowledgable, I was a peep here well before I was a member, and was a member when you were a mod. I just think that is “old school” and doesn’t make any sense…for compatibility anyway…longevity, maybe.