Does C1/C2 means any thing?

Today I had try to use plexWriter premium to burn one not certificate 52x CD-R.
I use plextor perfessional tools to check C1/C2 3 times, first time use 10-24 CAV check I go 5 error @ C2, second time I use 8x CLV no error, 3rd time I use 10-24 CAV check again, without error. what does it mean!

In HELP say existence C1/C2 errors are perfectly normal, since they can correct by the driver’s CIRC logic…

Does it mean I don’t have to worry about it, or my drive is defactive drive? or I have to use better media?
Please let me know if u have idea!!

Note : The cd-r have been burn can be read by other drives.

Thanks!!

A good burn should not show C2 errors

And fairly low C1 errors.

good burn:

Originally posted by alexnoe
good burn:

How about this scale > 1:1 + Logarithm Diagram ? Equals =

Btw, is it a good burn ? :wink:

Originally posted by BoSkin
Btw, is it a good burn?:wink:

Looks perfect to me.

The PlexTools Prof show E11 and E21, so the values of PT-Prof might be different. PT-Prof show E12 and E22 as C2 and E32 as “CU” (uncorrectable). The Premium is the first drive that significantly shows more C2-errors than the PX-40. I just hope you’ll not be too disappointed when testing your “perfect” media in the Premium :wink:

Kind regards Frederick

Originally posted by Frederick
I just hope you’ll not be too disappointed when testing your “perfect” media in the Premium :wink:

Thanks for the reply, Frederick !

Well, even if this happens, then it’ll be a good reason for aiming to reach that golden goal . :smiley:

Originally posted by BoSkin
Thanks for the reply, Frederick ! Well, even if this happens, then it’ll be a good reason for aiming to reach that golden goal .:smiley:

Hi BoSkin,

at least I was a bit disappointed. I have a “TDK Cyclone” which is in fact a 48x LiteOn at work. Since K_Probe does not work with WinNT 4.0 I tested with “DiscDoctor 1.04” and got some amazing results, very, very low C1-rates on good media.

When I cross-checked with the Premium, I got much more errors, although the relation between DiscDoctor and PT-Pro seems to be the same: when DiscDoctor shows two media e.g. with 0,5 and 1,1 C1/sector, the Premium will show those as e.g. 2,1 and 4,3 C1/sector.

But the Premium does show much much more errors, my previously so perfect media weren’t that perfect after all. The best result was with (no more available) Mitsui Gold Ultra, written at 8x speed on PX-W4824A (or Premium), those had 0,3 C1 errors per sector, zero C2 according to PT-Pro. DiscDoctor 1.04 showed the same media as 0,02 C1/sector in the LiteOn 48x drive.

Kind regards Frederick

Frederick,

most c1 errors are statistical and not always repeatable from one read session to another.

What does this mean?

Because the reading of a cd-r is not totally deterministic down to a submillimeter accuracy, the reader will sometimes get a wrong reading off a disc and report an error. At another time, when reading the same spot, it may not get the error.

Also, differences between cd-r media and drives can cause differences in C1/C2 results, although from what I’ve seen, these tend to be small differences, unless the drive has serious problems reading that type of disc.

Further, the speed of reading (when testing for c1/c2) is also a contributing factor - especially on discs which are somehow sub-optimal for the testing drive in question.

The professional testing machine manufacturers and testers recommend that testing be done at a minum speed (1x or 4x usually shows not that big statistical difference between them, but 52x compared to them will).

This due to the simple fact that the higher reading speed one uses for c1/c2 testing, the more the test is actually stressing the servo/optics capability of the reading drive and not the media. To put it simply, the faster the reading speed, the higher the amount of errors detected (on any drive I’ve seen used for testing) and more of those errors are not actual errors on the disc.

Now back to your specific question: why did PlexTools and KProbe report the same profile of c1/c2 errors, but PlexTools reported more of them?

Possible answers (I’m now guessing without knowing more of the situation at your end):

  1. You tested at a higher speed when using the Plextor drive

  2. Plextor drive has more difficulty in reading discs error free at high speeds using that particular media you tested

  3. There are actual differences between how Kprobe and PlexToolsPro command the drive to report c1/c2 error data (I think this is unlikely, but not knowing the specifics, I don’t think it’s impossible)

Could you tell us a bit more, by testing the same disc on both drives/software using 4x reading speed (I suppose both drives still support this speed in hardware) and report back the results. Also, if you have the time, use another disc from a completely different manufacturer and give us the low speed test results for those as well.

Best regards,
Halcyon

Originally posted by Halcyon

Further, the speed of reading (when testing for c1/c2) is also a contributing factor - especially on discs which are somehow sub-optimal for the testing drive in question.

The professional testing machine manufacturers and testers recommend that testing be done at a minum speed (1x or 4x usually shows not that big statistical difference between them, but 52x compared to them will).

@Halcyon,

Good ! Yet most of the attenders would feel themselves happy and proud when testing cd-r media @ Max :

i dont understand the logic behind 8x read instead of Max read, which can reflect everyday usage.

If low and max speed give the same result, then it is an indication for a disc which is easy to read .

:wink:

Originally posted by Halcyon
most c1 errors are statistical and not always repeatable from one read session to another.

You are of course right. Even when running the same test with same speed in sequence, the results may differ (although not too much).

To put it simply, the faster the reading speed, the higher the amount of errors detected

That’s my experience too. However I tend to run the tests with vMax, because that’s what most users do: read media with highest possible speed. This should represent every-day use. If a medium has good quality, the differences will not be great when reading slow or fast. The C1/C2 rates may differ, but there should be no uncorrectable errors.

Now back to your specific question: why did PlexTools and KProbe report the same profile of c1/c2 errors, but PlexTools reported more of them?

My assumption would be: the Plextor hardware reports more “E-types”.

  1. You tested at a higher speed when using the Plextor drive

On the contrary: PlexTools Prof. only allow 10-24x CAV for C1/C2 tests. Since KProbe does not work with WinNT 4.0 (my LiteOn drive is at my office and I’m stuck here to WinNT), I used the japanese DiscDoctor, which allows me to read at vMax (48x).

  1. Plextor drive has more difficulty in reading discs error free at high speeds using that particular media you tested

This may be so, I can’t say for sure.

  1. There are actual differences between how Kprobe and PlexToolsPro command the drive to report c1/c2 error data (I think this is unlikely, but not knowing the specifics, I don’t think it’s impossible)

That would be my assumption too: the hardware is different, we know that the Premium reports C1 as E11+E21, C2 as E22 (I suspect it’s actually E12+E22) and CU as E32 (uncorrectable C2 errors).

Could you tell us a bit more, by testing the same disc on both drives/software using 4x reading speed

That would take forever, but I’ll try to keep you updated. Haven’t got much time at work now …

But I can already give some good news: the Premium does not have the 9 sec. problem on CDS200 CDs, it reads 40x without any distortion.

Kind regards Frederick

When I search C1 on an original game (flanker2.0), Kprobe find some errors … I dont understand why ?

Originally posted by scaramanga
When I search C1 on an original game (flanker2.0), Kprobe find some errors … I dont understand why ?

Don’t worry, that’s perfectly normal. The readings aren’t bad at all, considering that many pressed original-CDs are worse than CD-R.

Kind regards Frederick

Plex Tools does not report c22 errors accurate. As you might know, if one makes audio cds with an audio recorder, between the tracks, where the laser stops burning (track at once), there are damaged data blocs. While a audio copy processor shows these e32 errors, the corresponding c22 errors are not shown by plextor.

I use a plextor 48/24/48 USB

> While a audio copy processor shows these
> e32 errors, the corresponding c22 errors are
> not shown by plextor.

What are these “c22” errors you’re talking about ?

Originally posted by spath
What are these “c22” errors you’re talking about ?

He probably means E22. But we are talking about Premium, while he is writing about PX-W4824A. The Premium does however report the E22 as “C2” and E32 as “CU” separately and correctly.

Kind regards Frederick

Frederick,

We all know what he probably meant, but only cjr can
tell for sure, so let him answer.

I mean c2-errors (these ones, plextools (non-prof.) reports)

But: If the CD has e32 errors (and a CDR has e32-errors, if you record it on an audio-recorder, where the laser stopps for the next track. When playing this CDR on an CDP, the CDP sends the e32-errorbit between these tracks), it has also c2-errors. But plextools does not show it.

Plextool does also not report the errors, which are on CDs with Cactus Datashild. For example, the CDP sends every some seconds E32 error-bit, plextools reports nothing (I tested it with Natalie Imbruglias last CD; when I tested it with Mel Cs newest CD, which has a newer version of Cactus, also the plextool reported c2, but less often than the CDP ).

PS: Every CDP sends an errorbit in the spdif-datastream, when uncorrectable errors occur (only DVD-Players and most audiorecorders don’t)

Originally posted by cjr
I mean c2-errors (these ones, plextools (non-prof.) reports)

But: If the CD has e32 errors (and a CDR has e32-errors, if you record it on an audio-recorder, where the laser stopps for the next track. When playing this CDR on an CDP, the CDP sends the e32-errorbit between these tracks), it has also c2-errors. But plextools does not show it.

Please bear in mind, that we have no info on which c2-errors the other Plextor-drives show. The PX-W4824A might (I dunno) show other E-types of C2. Since I have a PX-W4824A (and PX-W4012A) I did some cross-checks. Only the Premium showed C2-errors on some tested media, the other drives showed none.

We also know, that the Premium shows E22 as C2 and E32 as CU ("uncorrectable) according to manual. When I C2/CU test a medium with PT-Pro, it shows other values than e.g. a “readcd -c2scan”, because readcd can only query the “official” C2-counter in the drive. But we do not know, which errors are in this special chipset register.

Plextool does also not report the errors, which are on CDs with Cactus Datashild.

“readcd -c2scan” does however show many C2-errors on such CDS media. I did not use PlexTools (the normal ones) much in those days.

For example, the CDP sends every some seconds E32 error-bit, plextools reports nothing

I’m not sure, what to conclude. The CDP might have other reading capabilities than the plexwriter. The PT manual states, that C2 scans are done at 24x, because they wanted to show the errors, not to test the drive’s capabilities. C2 errors mean, that the drive was not able to get data correctly. Mostly this is due to a bad medium, but when you e.g. test media in different drives, you’ll soon see, that you get plenty of variation in error numbers, since some drives can read better than others. IMHO it’s not a good idea to compare error-numbers of different hadwares.

PS: Every CDP sends an errorbit in the spdif-datastream, when uncorrectable errors occur (only DVD-Players and most audiorecorders don’t)

That’s a very nice feature, and you show a good example why a “perfect” medium in a Plexwriter does not necessarily mean “perfect” for the CD-player. Even if the Plexwriter says “no errors”, the CD-player might still pick some up, because it’s reading capabilities are different.

Kind regards Frederick

> But: If the CD has e32 errors (and a CDR has e32-errors, if you record
> it on an audio-recorder, where the laser stopps for the next track.

You cannot say that a disc contain Exx errors : these errors only exist
in the error correction mechanism of the drive and therefore they depend
on the player, reading speed, etc. Now let me get this straight, are you
blaming Plextools for not reporting errors on regions of the disc that
are not recorded ? This surely would not look like a bug to me. Are you
even sure that Plextools reads these regions ?

> Plextool does also not report the errors, which are on CDs with Cactus
> Datashild. For example, the CDP sends every some seconds E32 error-bit,
> plextools reports nothing (I tested it with Natalie Imbruglias last CD;
> when I tested it with Mel Cs newest CD, which has a newer version of
> Cactus, also the plextool reported c2, but less often than the CDP ).

To me this just shows that your CDP worse error correction capabilities
than a plextor drive.