NEC ND-3520A Burner - Page 4

DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of the NEC ND-3520A drive with scratched / defective DVD media. For the 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 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 ND-3520A managed to read this test media without problems. It should be noted that the ND-3500A also managed to read this disc, but needed to lower its reading speed over the defects. This shows improved DVD error correction capabilities with the 3520A, since it did not have to lower its reading speed.

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 it but instead, defective areas of dimensions ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

Small speed fluctuations were introduced, in order to succesfully read the entire test disc. On the other hand, the process was completed with no read errors. It should be noted that the burner reached 16X reading speed.

- 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.

Again, the ND-3520A proved to be a very good reader, giving no errors and no speed drops.

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 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.

Excellent performance once again from the NEC drive.

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 from 0.4 to 3.0 mm.

According to the graph above, the drive shows excellent performance with the TDV-541 test disc. The scratched area was read without any errors.

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.

Again, the ND-3520A proves to be a very good reader. It had no problems reading black dots and fingerprints on the surface of the disc.

- Summary

Although the ND-3520A model is not the fastest reader available, users will not have any problem reading old, scratched media. High DVD error correction capabilities will ensure best possible reading with defective discs.