In the following tests, we examined the DVD reading capabilities of the drive 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.

Respectable reading with no read errors from the HP drive.

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.

Read speed drops quite a bit just where the reading process of the fingerprint-defective area begins, but then recovers. At the end, it varies between 13X and 15X. There are no reading errors, though.

- 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.

Relatively normal reading on the most part of this particular DVD error correction test, apart from the fact that it has a lot of momentary ups and downs for the duration of the disc.

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.

Reading speed drops momentarily on both layers just before the second defect where the fingerprints begin, exactly as it did with the TDR-825 test disc. No reading errors at all.

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.

There were no errors and the drive read the disc at 8X CAV. However, the graph is not smooth, revealing the drive's effort to cope with the scratched areas on 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.

- Summary

Overall, a very good error correction mechanism with DVD media.