In the following tests, we examine 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.

A very messy reading graph and the drive also produced errors, although not where we would expect over the defects area, but at the very start. There was also a drop in reading speed from just over 14X to around 10X after the defects are.

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.

Again not the best graph but this time no errors were produced.

- 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.

This is certainly an improvement and the drive reached 8X reading speed.

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.

Not a bad effort. Very similar to the reading response with the previous dual layer test disc.

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.

The drive managed to complete the reading of this test media, without any speed drops 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 also has 65 - 75 micrometer fingerprints.

Again, nice reading.

- Summary

The drive seems to do quite well with dual layer media but seemed to have problems with our single layer test media.