4x DVD+R/RW Roundup - Page 8

DVD Error Correction Tests

Plextor PX-504A

- Single Layer media

ABEX TDR-821

This is a single sided, single layer DVD-ROM with a 4.7GB capacity, in which there are scratches with dimensions from 2.6 to 4.8 mm. The following transfer rate picture comes from CDVD Benchmark v1.21.

As with the Mitsumi drive, Plextor PX-504A has also problems with the scratched DVD-ROM test disc. Many read errors occurred and the reading speed was reduced to 2x. Reading was resumed as soon as the drive could read back data from the unscratched areas.

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 a single difference that there are no scratches on it but defected areas with dimensions ranging from 0.5 to 1.1 mm. There are also fingerprints sized from 6.5 to 7.5 mm.

The drive did not have any problems to read the disc contents. The yellow dots correspond to the current speed in each area of the disc. No read errors were reported.

- 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 4.8 mm, in both layers.

Again many read errors were reported for both layers of the DVD-ROM disc.

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 defected areas and fingerprints. The dimensions of the defected areas are ranged from 0.5 to 1.1 mm and the fingerprints are sized from 0.065 to 0.075 mm.

This time the test was finished successfully with no read errors and the reading speed reached the 8x by the end of each layer.

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 model checks also the error correction capabilities of the drive and includes scratches from 1.8 to 3 mm.

As with the Mitsumi drive, the PX-504A could not read the scratched dual layer DVD-ROM disc and the test was terminated.

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 0.8 to 1.0 mm. It has also 0.065 - 0.075 mm fingerprints.

Black dots and fingerprints were not a problem for the drive. The test was successful, with a 3.44x average speed.