In the following tests, we check the DVD reading capabilities of the NEC ND-4550A drive with scratched / defective DVD media. For our tests, we used CDVD Benchmark and Nero CDSpeed. The reference test media comes from ALMEDIO.

ABEX TDR-821

This is a single sided, single layer DVD-ROM with 4.7GB capacity, and its surface has an artificial scratch varying in dimensions from 0.4 to 3.0 mm.

The following transfer rate picture comes from the CDVD Benchmark v1.21 transfer rate test.

A very smooth reading graph with just a clutter near the end but certainly no problems reading over the defects.

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, the only difference being that there are no scratches. Instead, there are defective areas, ranging in dimensions from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

Again, not problem with the defects and a very smooth graph.

- Dual Layer media

ABEX TDR-841

This is an 8.5GB dual layer single sided DVD-ROM disc with artificial scratches ranging dimensionally from 0.4 to 3.0mm, on both layers.

The NEC ND-4550 shows a near perfect performance with the specific test disc.

ABEX TDR-845

The disc is a single sided, dual layer DVD-ROM disc of a 8.5GBcapacity. The only difference between the TDR-845 and the TDR-841 is that the former includes defective areas and fingerprints.

The dimensions of the defective areas range from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micro meters.

Very good performance. Again, no errors reported.

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 was designed to inspect and adjust DVD-VIDEO players. The disc checks the layer switch operation from layer 0 to layer 1 and also includes test pictures and test signals on DVD sound files.

The current TDV-541 also checks the error correcting capabilities of the drive. It also includes scratches from 0.4 to 3.0 mm.

Good error correction capabilities, but the layer switch isn't as good as it should be.

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 meter fingerprints.

Excellent reading from the NEC drive.

- Summary

The NEC ND-4550A has a strong error correction mechanism and managed to read all of our discs successfully, without errors.