Disc Quality Tests
Having recorded the 7.93GB ISO file onto the Verbatim 2.4x Double Layer media at its rated recording speed of 2.4x to our review drives with DVD Decrypter, the next stage of our review will concentrate on Disc Quality.
As CDR-Zone.COM have found it to have the best support for Liteon-IT writers, K-Probe was used to check the media for any unexceptably high error levels using the Liteon-IT 1653S at its recommended scanning speed of 4x. So all the the Disc Quality test results shown here are from the DVD Video ISO compilations recorded on the review drives earlier in this review.
"Please note that you will need a compatible drive for doing these scans such as the Liteon-IT 1653S we have used. Other drives you could try include BenQ, NU TECH and ASUS branded writers."
"The less PI/PIF errors that are found on a media then in theory the better the chances are of longer archival life for the media without data loss becoming a problem".
Overview of Disc Quality Results:
The BenQ DW 1620A recording reported a total PIF value of 1533 with no values above 2.
The NEC ND 3520 recording reported a total PIF value of 1732 with with no values above 2.
The Pioneer DVR 108 recording reported a total PIF value of 1873 with no values above 2.
The Liteon-IT 1653S recording reported a total PIF value of 2106 with no values above 2.
The NEC 3500 AG recording reported a total PIF value of 2273 with no values above 2.
The HP Dvd6401 recording reported a total PIF value of 4780 with no values above 2.
All the Verbatim 2.4x Double Layer media reported higher PI and PIF values on the second Layer of the media which is normal for Double Layer media with all review drives. The BenQ DW 1620 recording reported the least value of PIF compared to all the other review drives.
Understanding the results:
A DVD has two levels of error correction. Any errors that make it through the first level are reported as PI, and any that make it past the second level are reported as PIF. PIF is what your DVD playback device will have to correct to achieve perfect DVD Video playback or Data transfer.
As long as PI levels stay under 300 then the recorded disc should be readable in any device at speeds above 6x. Single 'Spikes' above this limit can be ignored. Reported PI levels of upto 1000 can still be read by some devices, but we would question their long term archival life.
When reading the KProbe Disc Quality results for PIF values, please pay special notice to the bottom graph which we have nicknamed the 'safety zone'. As long as the PIF errors stay below 4 then the disc should be perfectly readable also with again single 'Spikes' ignorable but sustained areas above the safety zone would often reflect as skipping on DVD Video playback.
Different drives scan differently but staying within the 4 PIF 'safety zone' is always a good indication of a good quality recording.
These are to be used as a basic guideline to the quality of the recorded media only and our scans at 4x may be considered as such. DVD players only read at 1x whilst playing a movie and so if the media passes our Quality tests at 4x scanning speed and passes the following transfer tests then we are safe to assume compatiable DVD devices will not have any problems playing this media.
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