Good scan but reading errors ("PI/PO Scan on Taiyo Yuden")

Half an hour ago I burnt an official Unbranded Taiyo Yuden disc (TYG02), using my Plextor PX-712A @ 8x. I then scanned it for PI/PO errors using my Benq DW1650, which is supposed to be a good scanner.

The scan came out pretty good:

I then carried out a file/surface scan and a benchmark using the same drive:

The scan disk results showed that there were two bad blocks.

My question is that shouldn’t the PI/PO scan pick up the two bad blocks as a PO error or show any indication that there are errors on the disc.


I have also scanned it again to make sure it wasn’t a glitch and it came out the same.

I have scanned the same disc on a Pioneer DVR-111 and it came up fine:

The operative words for me are “supposed to be a good scanner”. I believe the BenQ1655 ,1650 to be one of the best if no the best burners - but fairly oridnary as a scanner. It can not read as well as it can write.

Pioneer drives (in my experience) are very good readers, so maybe that’s why the Pio completed the TRT without error.

Thanks for the replies.

I know what you mean about the Benq not being the best reader. However, I would have thought the PI/PO scan would have picked up the errors, but it didn’t and instead showed a perfectly acceptable scan.

The quality scan on the BenQ is not a PI/PO scan. It is a PIE/PIF scan. Only Pioneer writers do PI/PO scans. They are not the same thing.

@narendrapatel2 : what program are you using to show those images, I know this is off topic but if you would be so kind.

Of my app 15 burners (new and old) the Benq is in a class of it’s own as reader and it’s because it’s extraordinary bad. As writer it’s sometimes ok (as should be expected) sometimes bad (even on T02 media). Inconsistant is the keyword for this strange pc hardware :wink: Try scanning the disc again with the Benq and see what it says!

alan he/she is using an external image host called imageshack to upload the images and then copying the link using the picture option in advanced post.

@narendrapatel20 where’s the disc quality scan? Are you able to access the data stored on it using the BenQ?

alan1476: I am just saving the images using the save icon on the top-right of Nero CD-DVD Speed. I am then hosting it externally as I got errors when trying to upload it here.

CJ2: I have tried scanning the disc on the Benq three times now and it still says the same thing. I find it strange because I have never come across this with the Benq.

karangguni: I have seen the Benq report PO errors before, are you sure about this?

JayC30: Refer to the first post, which contains the quality scan done on the Benq. It also shows read errors on the same drive on scan disk.

Actually I am asking about the quality scan for the pioneer.

This is another example that Transfer Rate test is as important as other error scans.

Also, I’ve mentioned in another thread in BenQ forum, these particular BenQ drives (1650/1655) is quite sensitive readers, especially when it comes to high speed 16x reading, which unfortunately is the default. It might be good or bad depends on your purpose. For daily use it’s going to be frustating to see slowdowns while reading or even fails to read. For media testing purpose I think it’s a good indicator to see any slight error.

The BenQ drive reads at 16x while Pioneer at 12x. We can see that in the area where the bad file is, the BenQ drive reads at 9x while the Pioneer drive reads it at 7x and shows a small dip (at 698MB - exact point when BenQ failed). If you want to compare, put another Transfer Rate test of that particular media on another drive that can read at 16x.

Alternatively, try to read the media on BenQ drive at 12x and see if there is still an error. To do it, set Nero CD-DVD Speed > Options > Standard Tests > Read Speed = 12x Selected. Please post the result here.

As zevia mentions, the Benq can be sensitive at full speed. While it IS unusual and very uncommon to see a failed transfer rate test and yet show nothing on the PI/PIF test, the two tests ARE at different speeds. It would be interesting to see what the PI/PIF test reports if you test the disc at maximum speed. Conversely, it would also be interesting to see what the transfer rate and scandisc shows if testing at a slower speed such as 8x.

The PO error bit you saw with a BenQ writer is in fact not PO errors but PO failures (POF). This is going to get a little confusing here but I’ll try to explain -

With PI/PO scans (as performed with a Pioneer writer on DVDInfoPro) :
PI=PIE (Parity Inner Error)
PO=POE (Parity Outer Error)

With PIE/PIF scans (as performed on a BenQ with Nero CD Speed’s quality scanning) :
PIE= Parity Inner Error
PIF=Parity Inner Failure
POF=Parity Outer Failure

As you can see, both types of scans measure PIEs, but apart from that they measure totally different things. So the two types of scans are really different.

One thing I am not sure about is quality scanning done on Pioneer 110/111 writers with Nero CD Speed 4.50 and above (which support Pioneer writers). I’m not sure if that PIE/PIFs are really being reported.

:iagree: That about sums it up.

PIE/PIF scanning does NOT show possible unreadable blocks, as user data is not read during a PIE/PIF scan. The opposite is also true: you can see POF errors in a Benq scan with a disc that is still readable.
[B]DrageMester[/B] and myself, as well as other posters, have mentioned cases of good-looking scans of discs that failed a TRT (or a scan disc “reading test”) in at least one drive. So these cases, while scarse, should remind everyone that PIE/PIF scanning, while being unvaluable for given uses (comparing burns, checking for degradation), are not the “one-fits-all” testing that many users have come to think it is.

If one really wants to be 100% sure of the integrity of one’s data, one [I]needs[/I] some sort of [I]real-world reading test[/I], like a transfer rate test.

The other lesson is the same old one, which is: the behaviour of a disc in a given drive is not predictive of the behaviour of the same disc in another drive.

As a sidenote, I kinda concur to the idea that Benq drives are peculiar readers, to say the least. Though I think they’re fantastic burners. :slight_smile:

I agree 100% with this.

You can find my posts and scans on the same subject in this thread.
Unfortunately the attachments can’t be viewed at the moment due to problems after the CDFreaks server upgrade.

In my opinion this is a bug in BenQ POF reporting, since the BenQ can report Parity Outer Failures, and yet it doesn’t always report POF even when it cannot read a sector. :frowning:

In my case, the BenQ couldn’t read a particular sector at any reading speed, and it only showed POF in some scans but not in a reliably way. No other drive I tried had any problem reading the same disc.

You have to keep in mind that the PI/PIF test is being run at a different speed than the TRT and Scandisc. While this is an extreme example since there is basically NOTHING suggesting problems on the PI/PIF test yet an unreadable spot in the other two tests, it still is important to note that different testing speeds can occasionally change the outcome of a test much more than one would expect.

Then again, even a PI/PIF test at maximum read speed may still not indicate a problem, that remains to be seen. It would certainly be a good sign if a PI/PIF test at maximum would show elevated errors at the read error.

For anyone that is still interested, I have ran some more tests on the disc.

[B]Benq DW1650[/B]

[B]PIE/PIF scan at maximum speed[/B]

[B]Transfer Rate Test at lowest speed[/B]

[B]Plextor PX-712A[/B]

PIE and PIF tests are done at the default speed of 2x. The Plextor seems to read the disc just fine with no read errors.


[B]Transfer Rate Test[/B]




[B]NEC ND-3540A[/B]

[B]Transfer Rate Test at lowest speed[/B]


[B]Quality Scan[/B]

Scanning at 16x! The standard for BenQ is 8x.

I always run both TRT and quality scans for my own peace of mind, I have had discs fail TRT on the PC but play perfectly on the DVD player, which is my real world test of coasterdom.