DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of Memorex DVD+/-RW True-8x with scratched / defective DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed. The testing 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 drive managed to read the disc accurately without any read errors. As shown on the above graph the drive reached the 13x maximum reading speed at the end of the single layer disc.

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

Memorex managed to read Abex TDR-825 test without any errors. The drive passed the effective areas with high accuracy, but when the reading process reached the fingerprints area at the 1.450.000th sector, the reading speed decreased from 11x to 5x. The drive maintained that reading speed until the end of the effected area and increased it again when it passed it.

- 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.

Memorex True-8x once again performed well and managed to finish the test without posting any errors. The drive reached maximum reading speed 8.6x, at the end of each layer.

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).

On the previous tested Abex 825 TDR test disc, Memorex needed to slow down it's reading speed while on the fingerprints area, in order to finish the reading test without errors. On this test despite the fact that fingerprints and defected areas have exactly the same dimension, with the 825 test disc the drive managed to read accurately the two layers and passed both effective areas and fingerprints without slowing down the speed.

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 layers 0 to 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 dual layer 541 DVD-ROM was read under CAV mode. NeroCD Speed reported high Full seek times, something that seems to be a characteristic of the drive, with Full seek returning 309ms. However the graph above shows a perfect result without reading problems when switching from layer 0 to 1. After the test ended the reported average speed was 6.33x.

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 micrometres high fingerprints.

 

 

Once again the reading test ended without read errors. NeroCDSpeed reported CAV mode for reading strategy, high Full seek times and average speed at 6.34x.