NEC ND-2510A Recorder - Page 4

DVD Error Correction Tests

In the following tests we examine the DVD reading capabilities of the NEC ND-2510A drive with scratched / defective DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed. The reference test media comes 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 screenshot comes from the CDVD Benchmark v1.21 transfer rate test.

The drive can read DVD media up to 12X. The scratched area did not affect the reading process. NEC's drive showed very good behavior with this disc, and no errors were reported.

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 the difference that there are no scratches on it but defective areas of dimensions ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

Again, the ND-2510A had no problem reading this test disc. A continuous, clean line was produced giving no errors during the reading process. The disc was read as if there were no defects at all.

- 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

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As is obvious from the screenshot above, the drive had problems reading this test disc. The red dots indicate read errors during the reading process. The test could not be completed by the drive because of unreadable data on the disc. Reading speed was reduced automatically by the drive, but even so, the ND-2510A could not complete the reading process for the entire disc. This is a weak point of the NEC drive, making it a rather bad DVD Dual Layer reader.

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 checks also the error correcting capabilities of the drive and includes scratches from 0.4 to 3.0 mm.

As it is well shown above, the ND-2510A was unable to read this test discs well. Again, according to this reading behavior, the drive can be described as a bad reader. It started to read at 1.91X, lowered the reading speed for an instance, and stopped reading near the end of the first layer, having reached a speed of 4.49X.

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.

The ND-2510A started to read at 1.91X as before, and reached a maximum speed of 4.59X. Although the reading speed was not as high as other 8X DVD recorders, we were happy to see that no read errors were produced.