In the following tests, we examine the DVD reading capabilities of the LiteOn SHW-1635S 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 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.

As we can see from the above graph, the drive managed to read all the way to the end of the test, without any drops in speed, although the max reading speed was not achieved, with the drive reaching only as high as 8X.

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 max reading speed achieved was 16X with flawless reading once more. The drive's mechanism did not have any trouble reading both defective areas, producing a smooth speed graph.

- 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.

Both layers were read without any errors and a max reading speed of over 8X.

ABEX TDR-845

This test 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 discs is that the first includes defective areas and fingerprints. The dimensions of the defective areas ranges from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micrometers.

Last graph and the most difficult task for the drive's reading mechanism, as each layer contains two defective areas which the drive has to read over. In both layers, the error correction mechanism made quick work of the defects, reaching a max reading speed of 8X and with no errors or speed drops.

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 on 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.

Job well done with the 541 test media. Max speed reported was 8X and a smooth graph was produced.

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.

Same performance as the previous test disc, with perhaps in this case, a much smoother graph. Excellent reading.

- Conclusion

All the above tests indicate very good DVD error correction capabilities, even though the max reading speed was not achieved in all cases.