In the following tests, we examine the DVD reading capabilities of the drive (error correction) with scratched / defective DVD media. For the tests, we used CDVD Benchmark and 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 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.

Flawless reading, without any problems and without dropping speed.

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.

- 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.

Here too, the drive continues its good reading performance.

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.

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 Pioneer drive failed to read 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, producing a smooth speed graph.

Summary

Overall, the DVD error correction mechanisms are generally good, with an exception the "scratched" dual-layer DVD Video disc. Failure on the TDV-541 is not something rare among DVD drives, as many other drives that we recently tested failed to read the disc.