In the following tests, we examine the DVD reading capabilities of the drive with
scratched / defective DVD media. For the tests we used Nero CDSpeed. The reference test media comes from ALMEDIO.
- Single Layer media
ABEX TDR-821
This is a single sided, single layer DVD-ROM with 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 Nero CD DVD Speed transfer rate test.

No reading errors can be reported. The device manged to read all artificial errors; a smooth line all the way to the end of the test.
ABEX TDR-825
This is also a single sided, single layer DVD-ROM of 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 instead
defective areas of dimensions ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

In this case, the drive performed relatively well, even though we can see a drop of speed at the end, nera the completion of the test. It gave a successful reading once again.
- 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.
. 

An excellent reading. The graph shows smooth lines on both layers.
ABEX TDR-845
The disc is a single sided, dual layer DVD-ROM disc with 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 defective areas range from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micrometers.


No match to report here, the graph speaks of itself.
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 disc checks the layer switch operation
from layer 0 to layer 1 and also includes test pictures and test signals for
DVD sound files.

The current TDV-541 also checks the error correcting capabilities of the
drive and includes scratches from 0.4 to 3.0 mm.

Not a very smooth graph, only because of the drop of speed the LG drive managed to read over the defective area of the drive. The test was completed successfully with no errors to be reported.
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 disc's surface, sized
from 0.4 to 1.0 mm. It also has 65 - 75 micrometer thickness, fingerprints.

A show off of the burners error correction capablitites.. Smooth line with a slight, negligible drop during the layer change.