DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of the Optorite DD0405 drive with scratched / defective 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.

The above screenshot shows that the Optorite drive had some problems with the 821 test disc. Despite the fact that the test ended without errors, the drive didn't manage to read it under CAV. However, using the 5x CLV mode the disc was read accurately.

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 the surface and instead defective areas ranging in dimensions from 0.5 to 1.1 mm. There are also fingerprints with height between 65 and 75 micrometers.

The Optorite DD0405 managed to finish the 825 Abex test fast and accurately. The reading process started at 5x and under CAV mode finished at about 12x.

- 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.

The above screenshot shows that Optorite managed to finish the Abex TDR-841 test disc without errors (red spots). Again the drive behaved as in the case of the corresponding single layer disc, lowering the reading speed to 5x to maintain reading accuracy. Also notice the large number of speed changes (large group of yellow dispersed dots) at the beiginning of the disc, where the drive first encounters the scratches.

ABEX TDR-845

This disc is a single sided, dual layer DVD-ROM disc with capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 is that the first includes both defective areas and fingerprints. The dimensions of the defective areas range from 0.5 to 1.1 mm and the fingerprints have height sized from 65 to 75 microns (micrometres).

The above screenshot shows that Optorite managed to read the effected areas of the first layer without problem while top speed reached was about 9x.

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 sized from 0.4 to 3.0 mm.

The reading process started at 3.56x under CAV mode but when the drive reached the defective area the speed was decreased from 5.2x to 4.4x. On the other hand the above graph shows smooth switch operation from layer 0 to layer 1. The test ended without producing any error messages.

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer Video/S-2 disc with a capacity of 8.5GB. The TDV-545 includes artificial black dots on the disc's surface, sized from 0.4 to 1.0 mm. It also has 65 - 75 micrometre high fingerprints.

The Optorite DD0405 read the Abex 545 test disc without problems. Both layers were read smoothly and accurately while the reported seek times and average speed were very good.