LiteOn SOHD-167T - Page 4
DVD Error Correction
Tests
In the following tests we examined the DVD reading capabilities of
the 167T drive with scratched / defective
DVD media.
For the tests we used CDVD Benchmark and Nero CDSpeed. The reference test
media
come
from
ALMEDIO.
- Single Layer media
ABEX TDR-821
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
rate test.
The LiteOn SOHW-167T read the disc at 16X CAV and the scratched area did
not affect the process. The disc was read accurately and no read errors
were
reported.
Below are the corresponding graphs for the LTD-163/165H:
ABEX TDR-825
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 defective areas of dimensions
ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and
75 micrometers.
As before, the disc was read without any "read errors" and the
test was finished successfully.
There was a short duration reading speed drop just before the third step which
didn't affect the process however.
Below are the graphs for the LTD-163/165H:


- Dual Layer media
ABEX TDR-841
This is an 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches
of dimensions ranging from 0.4 to 3.0mm, on both layers.
The drive read both layers without any major problems, as the above graph
shows.
Below are the same graphs for the LTD-163/165H:
ABEX TDR-845
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
defective areas and fingerprints.

The dimensions of the defects range
from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micro meters.
The
drive passed the fingerprint defects without any reading speed drop
and finished the test without problems.
Below are the graphs for the LTD-163/165H:
ABEX TDV-541
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 3.37X and reached 8.06X at the 4.0GB point,
where the drive changed layer and reduced its reading speed till the end. The
drive finished the
reading
process
normally, without errors or problems.
ABEX TDV-545
The
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 micrometer
fingerprints.
Black dots and fingerprints on the disc's surface did not create any reading
problems, and the drive finished the task successfully.