Is KProbe unreliable?

vbimport

#1

I recently applied the gsc2 firmware to my 451@851 and to my surprise I was now able to succesfully burn (and verify) some old cheap mirror disc I had. Older firmwares would not complete the verify phase. I could even burn the disc at 8x !!!

I then did a Kprobe scan and expected PI to be much above 200 because of the cheap quality disc. But it looks like the below (burned at 8x ). I was very happy.

Now, I have used up all my Mirror disc and yesterday I wanted to watch a backedup movie (a Mirror disc) and during playback it would skip and freeze. About halfway into the movie the dvd player stopped responding. I put the disc into the liteon 851 and tried to copy the data but I could not. Cyclic redundance check error. I checked the disc: no scratches or fingerprints etc. I redid the Kprobe and the scan was still great.

Now, I’m checking the rest of the discs. I know some data has been lost (2 discs so far).

I don’t trust Kprobe anymore.


#2

Hi,

I encountered similar problems. I patched my 451@851 with the new GSC2 and burned 2 discs. Incredible I thought, very good results and I was happy because with the older firmwares I always got high PI and P0 in the first fifth of each disc, even when the DVD played flawlessly in all of my drives and standalone-player. Then I decided to scan some DVDs again, that I burned with older firmware versions months ago.

The results were strange, because even the old discs which were reported to have these high error rates in the first fifth showed the same results as the discs burned with GSC2. So not the writing has been improved but the reading strategy.

It isn´t good only to trust KProbe. I always check my discs with Nero CD-DVD speed, with different DVD-Drives and with my stand-alone player. When the discs that can be read with all these drives show nice scans in KProbe, well then it is o.k. and I can burn more of these discs with the same settings. When it comes to reliability I more or less trust “real” tests.


#3

I’d have to agree that Kprobe is “unreliable”. At least, you can’t really rely on it as any sort of an absolute measurement of anything. The same DVD that reads PI peaks @ about 12 on one of my burners (LDW-431S) comes out with a PI around 200 or more on my 811S.

This tells me it’s more of a relative thing. Find out what works for you on your stand-alone players.

But I do pity those who only have one DVD burner. At least with two you could always leave one as your standard Kprobe measurement setup (don’t touch the firmware).

Otherwise, if you want to see the different firmware revision’s effects on burning quality, you have to make sure you always use Kprobe with a set firmware revision level to make sure you’re comparing apples to apples.


#4

Originally Posted by Frodnat
It isn´t good only to trust KProbe. I always check my discs with Nero CD-DVD speed, with different DVD-Drives and with my stand-alone player.

I tend to agree.
I have had discs that give ‘perfect’ KProbe scans , but unreadable error when scanned using Nero DVD Speed with both my 48161H Combo and 451@851 Burner, where as discs with ‘worse’ Kprobe scans read perfectly.

There is seems to be more to a good burn than getting a good KProbe result.


#5

Read this post!
Strange results!

http://club.cdfreaks.com/showpost.php?p=610178&postcount=66


#6

Wow so what’s the point of kprobe then??? Its idiotic if it says the disk is fine, but you can’t even read it later.


#7

Kprobe is neither reliable nor unreliable, neither accurate nor inaccurate. It does not possess such qualities. It’s just the messenger. As is clearly stated in a number of related threads, you cannot compare reading performance from different drives. The same applies to scans with different firmwares. Read-errors are relative, not absolute.


#8

Originally Posted by rdgrimes
Kprobe is neither reliable nor unreliable, neither accurate nor inaccurate. It does not possess such qualities. It’s just the messenger. As is clearly stated in a number of related threads, you cannot compare reading performance from different drives. The same applies to scans with different firmwares. Read-errors are relative, not absolute.

Agreed.
Just don’t think that because you get ‘the best ever’ scan with KProbe that you have a disk that will read well. There is more to it than that (just wish I knew what).
As I posted previously I have had Nero DVD Speed give unreadable error on discs with ‘perfect’ Kprobe scans - (approx PI Max 12 Ave .5 Total <10000 PO Max 4 Ave .0 Total ~300) while ‘worse’ scans (but still within spec) read perfect with Nero.

edit all done with the same drive, same firmware, same pc, etc etc


#9

You’re not understanding what is being reported. There a number of explanations for what you have seen, but KProbe is not one of them. It does nothing but record what the drive is “seeing”.


#10

Sorry seems I’m not explaining my point very well.

Just trying to say that maybe KProbe shouldn’t be relied on as an indicator of what is a “good” or “bad” disc as much as it seems to be.
It is a good tool for showing changes in hardware / firmware on a particular system - or to compare different media, but I also think that discs should be run through Nero DVD Speed as well.


#11

So uhm, if I run kprobe on a burn I just did using some Princo disk, and then run it on some Ritek disk…and the Ritek disk looks better on the Kprobe…its still possible that I can read the Princo but can’t read the Ritek?

I guess I don’t get it, but from what I’m reading it seems like a useless tool if it can’t even tell me if a disk is readable or not. I don’t think its the fault of kprobe though…but the process itself. So it seems all sorts of variations might cause errors…I can buy that. Vibrations, dust, whatever…but what I can’t buy, is you get a GREAT score on it, yet later can’t even read the disk!!? That doesn’t really make sense at all. So what the hell is kprobe doing?? Pretending to read the disk?


#12

Sure, why not? Look at OC-Freak’s reviews of DVD burners - he always supplies a screenshot of CDSpeed transfer rate test along with a Kprobe PI/PO scan. DVD media tests forum encourages everyone to post any information relevant to the media performance (CDSpeed, DVD player or XBox compatibility, etc). Not many people do this, though. In addition, the Liteon forum is full of PI/PO scans, while transfer rate tests aren’t very popular. Perhaps, this make some people think that a good Kprobe scan is a definite indicator of the disc quality. It’s not, at least not always. Kprobe is just a tool available for Mediatek chipset based burners. That doesn’t mean you have to rely solely on PI/PO level reported by Kprobe when you evaluate media quality. You can run CDSpeed quality test to see PI/PO, after all.

You can run CDSpeed, however, your Liteon burner may be a much better reader than a standalone DVD player because of a better error correction mechanism, and even with perfect CDSpeed results you may have problems with playing the disc in your player.

negativecreep, I’m not aiming my post directly at you, but rather at these forum members, who talk about Kprobe’s unreliablilty.


#13

Even if it is just a messenger what can we use Kprobe for? All my Ritek discs and TY disc scans worse than my Mirror discs. Yet I have no problems reading the Ritek and TY discs in any drive.

Kprobe gave me the impression that these mirror discs are not just good, they are great! But in real life they are worthless. Two of the discs where not even readable on the Liteon 451 that had written the disc.

If the difference between Kprobe scans and the actual readability IN THE SAME DRIVE is so big then the Kprobe scan is unreliable, IMO.


#14

FALSE Kprobe is as reliable as the drive (your post should be titled LITEONS are not reliable!) first ive always gotten suspicious looking scans with some liteons 411/811s (i think the 812 is the most reliable scanner out there imho).But also remember Kprobe just a tool its as relieable as any other tool it measures PI/PO (PIF) BLER on a liteon drive, it doesnt give you read errors which can occur even with low pi/pos (cdspeed3 may catch them as POFs on some drives). just becuase a disk has low pi/pos doesnt mean it doesnt have read errors or bad jitter. problem is liteons dont measure jitter so you need another drive (nu/benq do). Show us your supposed perfect scans and id like to see a cd speed run too plus a surface scan…software glitches can also cause readerrors as well as dye defects on disk that occur after a burn.

In conclusion a good kprobe scan alone does not ensure readability nor does it say you have a good disk never did and never claimed to be its just a BLER scan. But i can tell you my kprobe scans are very reliable in conjunction with a cdspeed test and a surface scan.


#15

Id be real suspicious of that big block of pos on your scan above…so imho kprobe is accurate in telling me something…remember just the total number of pos is not neccesarrily meaningful a big red block of POs is suspicious…id say kprobe is showing you something you ignored a large block of ecc errors clustered together (not a great scan from me looking at it). and im betting that your read errors are in that address range. theres a good reason why kprobe gives you a graph and not just numbers :wink:


#16

your post should be titled LITEONS are not reliable

Or better yet: optical discs are unreliable. As as been covered multiple times around here, and in this thread , there are numerous reasons for varying disc scans/checks, but the most common cause is the disc itself. I have never, in hundreds of DVD tests, seen a high quality burn that exhibits any of these types of issues. Likewise, I have never seen it on discs burned in my NEC (see “high quality”), but I do not use crappy media either.
It’s also good to remind all that CDSpeed scandisc does not report PI/PO, POF, or anything like that. The biggest reason for the differences in “readability” between Kprobe scans and CDSpeed is the read speed control that is absent from CDSpeed scandisc.


#17

ie csspeed scans disks at full speed hence errors may occur where as kprobe at 4x they do not show up as much (but that big red block of pos still would have me suspicious of his disk quality!). id like to see a kprobe2 scan at 8x on the same disk bet his errors go up greatly :wink: remember crappy media will give greatly varying error rates based on the speed you run kprobe at…where as good media will not vary much :wink:

so i think this thread should be named Kprobe interpeted incorrectly is unreliable. :iagree:


#18

But how am I supposed to distinguish between a poor disc and a good one using Kprobe? I’m using Ritek G04, Ricoh’s, TY and they scan the same or worse than these mirror discs. But it’s only the mirror discs that can’t play in any dvd player without freezing and stuttering.

What does a good Kprobe scan look like in your opinion?

Show us your supposed perfect scans and id like to see a cd speed run too plus a surface scan…

I’m not sure I know what you mean? IMO, there is no such thing as a perfect Kprobe scan. I thought the above scan I posted was supposed to be a “perfect scan” but the disc has extremly poor readability. I have discs that has much higher PI/PO values that reads without a glitch. I use Nero DVD-speed for testing. I feel Nero is a bit more like a real-life test.

In conclusion a good kprobe scan alone does not ensure readability nor does it say you have a good disk

Exactly! So what can we use Kprobe for? We can get a pi/po/bler readout, but what can we use these numbers for? People in this forum use Kprobe to measure burn quality or media quality. I can provide you with a scan of a g04 or Ricoh disc when I get home for comparison.

I’m not trying to bash Kprobe or it’s author. I know he spent a lot of time making this program and he is giving it away for free.


#19

It is reliable. Especially in extreme cases.

My friend had some princo that wouldnt work, he didn’t know why. They stopped in his DVD player. Used kprobe - 1600 PI…

Test my working discs = 12 ave PI

Wow, kprobe was right. Wasn’t it.

Tested another mates discs that would not work. He had a liteon DVD writer, and it reported something like 900PI. Makes perfect sense.

Sometimes some DVD players are fussy to all burns, be them good or bad.

But most players play good burns and can handle a reasonably high PI/PO count.

Basically- if it far exceeds the standards - don’t expect it to work. If it’s within standards and the disc is good quality, you have DVD incompatibility problems.

It’s all about finding the perfect discs for your burner. So far, for me, that is TYG01.


#20

And Kprobe is telling me that the perfect disc for my burner is cheap Mirror discs, yet most dvd drives (including my liteon drive) can’t read it without slowdown and hickups. About 10% of the Mirror discs have unrecoverable readerrors.