DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of Philips DVDR824P drive with scratched / defected DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed . The reference test media come 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.

Philips DVDR824P read the 821 test disc without reporting any read errors. The yellow dots indicate that the drive gave back different reading speeds for each reading retry, due to the scratched areas.. The disc was read accurately at 12x CAV.

ABEX TDR-825

This is also a single sided, single layer DVD-ROM of a 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 defected areas of dimensions ranging from 0.5 to 1.1 mm. There are also fingerprints sized between 65 and 75 micrometers.

As in the previous test, no read errors occurred with this disc. The drive read the disc under CAV mode but did not manage to reach maximum reading speed of 12x. The hardest areas on the specific disc seems to be the artificial fingerprints, where the drive slowed down to finish the task at 11x CAV.

- Dual Layer media

ABEX TDR-841

This is a 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches of dimensions ranging from 0.4 to 3.0mm, in both layers.

The dual layer DVD-ROM disc was read just like the single layer effected DVD-ROM (821 Abex test disc). Regardless the fact that the transfer rate graph is not solid, the Philips drive managed to read each layer at 7x CAV and finished the test without posting any read errors.

ABEX TDR-845

The disc is a single sided, dual layer DVD-ROM disc of a capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 is that the first includes defected areas and fingerprints. The dimensions of the defected areas range from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micro meters.

The defected areas did not allow the drive to reach the maximum expected speed (8x), but what really matters is the reading accuracy.

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 discs check the layer switch operation from layer 0 to layer 1 and also include test pictures and test signals for DVD sound files. The current TDV-541 checks also the error correcting capabilities of the drive and includes scratches sized from 0.4 to 3.0 mm.

The 541 test disc was not a problem for the Philips drive. Besides the momentarily slow down of the speed at the beginning of the first layer the disc was read accurately at 7.61x CAV.

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 has also 65 - 75 micro meters fingerprints.

Black dots and fingerprints on the disc surface did not create any reading problems, and the drive finished the task successfully.