Low PI/PIF Rates, high POF rates ?!? (and other weirdness)

vbimport

#1

IMO this is pretty strange. I scanned this disc less than 1 month ago and it was perfect.

Now I scanned it again two times in a row. The first time I had many POF concentrated in a small area, the second time no POF. Also in the version with high POF, there was low PIF, which is clearly contradictory. Scans are below. (Burned on a PX-708A.)

Also my error scanning is acting strangely in other ways:

  1. For example very often in CDSpeed, it says that the test failed to initialize.
  2. Sometimes it tries to scan above 100% even though the disc size is set to auto. (Areas above 100% are reported as POF errors.)
  3. Often I get very regular ‘ECC skipped’ messages in KProbe, always at the same points on different pressed DVDs.

The only thing I can think of is that I bumped the drawer of the drive with my knee yesterday, although the drive load/eject mechanism still works just fine. The only recent hardware change is that I physically uninstalled the PX-708A.

Does anyone know why this weirdness is happening?


#2

post deleted by Jucius_Maximus


#3

Kprobe does not measure POF. The “errors” reported here can often be caused by accessing the IDE bus during the scan. This would be opening a program than scans the bus, or running some related program, even Explorer can do it.
The messages about skipped sectors are generic messages that relate to the above.


#4

Once again you have enlightened me. :bow:

I was always under the impression that Error = POF, but clearly I was mistaken. Thank you for the information.

I did run KProbe at a higher priority than other programs. Also, that drive is on an ATA133 card and the only other thing on the channel is a Pioneer DVDROM, which was not used during these tests.

Could accessing other IDE channels on that ATA133 card cause these ‘errors’ ? There is a HDD on the other IDE channel that was accessed during the first test.


#5

Could accessing other IDE channels on that ATA133 card cause these ‘errors’

Yes, if a program is polling the IDE bus. It can vary a bit and is not always predictable. Many programs can poll all IDE devices as a matter of routine. Nero is one, Explorer does it all the time. I even have an old 16-bit database program that does it. Any interruption in the flow of data to Kprobe will produce these errors, as it has the drive “locked”.
The error itself can vary too, but these erors in Kprobe are “scanning errors”, not “read errors”. Hope that makes sense.


#6

Yes, thank you for the input. I’ll have to rethink a lot of these results now that I am the wiser.


#7

The scans look very similar to me apart from the burst at the end. Could have had some dirt on the disc which came off before or during the second scan.

Try scanning a disc then drop it on the carpet to pick up some dust and scan it again - see what that does to your scans (actually maybe not you will dust in the drive). Try dabbing the disc surface with a marker pen you will see the result in a scan.


#8

That’s a good point, though my question was about the error spikes in the first scan as opposed to that burst at the end. This has been answered to my satisfaction by rdgrimes.

As to the other issues with KProbe scanning above 100% and stuff I’m still hoping someone will say something or I can find some solution.

Thanks again for the info.


#9

As to the other issues with KProbe scanning above 100%

The 411 drive was known to do this, especially with some firmware versions. Usually it’s because the disc is not closed.