In the following tests, we examine the DVD reading capabilities of the drive with scratched / defective DVD media (error correction). For the tests, we used Nero DiscSpeed. The reference test media comes 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 reading process was completed successfully, although the drive slowed down in the beginning of the disc.
|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
No, slowdowns in the beginning |
No |
No |
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.


No reading problems here.
|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
No |
No |
No |
- 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.


Same as before, successful reading without any speed fluctuations or read errors.
|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
No |
No |
No |
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.


Great reading here.
|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
No |
Yes |
No |
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.


|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
Yes |
No |
Yes |
This time a read error was reported before the drive shift from layer 0 to layer 1 of the disc.
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 also has 65 - 75 micrometer fingerprints.

Flawless reading here.
|
Optiarc AD-7260S |
Optiarc AD-7240S |
LiteOn iHAS524 |
| Read errors |
No |
No |
No |
Summary
Overall, the DVD error correction mechanism is good although it could be even better, especially with scratched dual layer DVD-VIDEO discs.