DVD±RW Recorder -
DVD Error Correction
In the following tests we examined the DVD reading capabilities of
the DRU700A drive with scratched / defected
For the tests we used CDVD Benchmark and Nero CDSpeed . The reference test
- Single Layer media
This is a single sided, single layer DVD-ROM with a 4.7GB capacity, and its
surface has an artificial scratch of dimensions varying from 0.4 to 3.0 mm.
The following transfer rate picture comes from the CDVD Benchmark v1.21 transfer
The Sony DRU-700A read the disc at 12X CAV and the scratched area did
not affect the reading speed. The disc was read accurately and no read errors
The performance reveals high error correction capabilities with scratched single
layer DVD-ROM discs.
This is also a single sided, single layer DVD-ROM of a 4.7GB capacity. The
data structure of the disc is exactly the same as that of the TDR-821, with
the difference that there are no scratches on it but defected areas of dimensions
ranging from 0.5 to 1.1 mm. There are also fingerprints sized between 65 and
As in the previous test, the disc was read without any "read errors".
There was a small drop in reading speed just before the fingerprint
defective area, but the test was finished successfully.
- Dual Layer media
This is a 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches
of dimensions ranging from 0.4 to 3.0mm, in both layers.
The drive didn't have any major problems as the above graph shows.
The disc is a single sided, dual layer DVD-ROM disc of a capacity of 8.5GB.
The only difference between the TDR-845 and the TDR-841 is that the first includes
defected areas and fingerprints. The dimensions of the defected areas range
from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micro meters.
Here we notice the same behavior as with the single layer disc. When the
drive enters the fingerprint defective area, the reading speed drops for a
while but quickly regains speed and finishes the test without any problems.
The TDV-541 is a single sided, dual layer DVD-VIDEO disc, with a capacity
of 8.5GB.The disc is based upon the TDV-540 series which is designed for inspection
and adjustment of DVD-VIDEO players. The discs check the layer switch operation
from layer 0 to layer 1 and also include test pictures and test signals for
DVD sound files. The current TDV-541 checks also the error correcting capabilities
of the drive and includes scratches from 0.4 to 3.0 mm.
The reading process started at 3.54X and reached 8.45X at the 4.0GB point,
where the drive changed layer and reduced its reading speed till the end. No
serious problems were noticed, very small glitches but the result is good.
TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer
DVD-VIDEO disc with a capacity of 8.5GB. The TDV-545 includes artificial black
dots on the data surface, sized from 0.4 to 1.0 mm. It has also 65 - 75 micro
Black dots and fingerprints on the disc's surface did not create any reading
problems, and the drive finished the task successfully.