In the following tests, we check the DVD reading capabilities of the Plextor 755A 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 a 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.

Even though the drive dropped speed over the last section of the defect area, the PX-755A managed to successfully read over the defective area, achieving a 16X reading speed at the end.

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 on it. 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.

Excellent reading, with no drops in speed and a smooth line from start to finish. Quite impressive, since most recent drives are only able to read this disc at a max speed of up to 8X.

- 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.

Both Layers read successfully, with the reading speed maxing out at 12X.

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.

Once more good reading in both layers. The artificially defective areas on this media were no match for the drive's error correction mechanism, which read the whole disc with no drops in speed and reached the max reading speed available.

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.

As we can clearly see in the graph above, while the drive managed to complete the reading of this test media, it was with a severe cost in speed. Drops in reading speed occurred in both layers, while the major drop is just after the start of the second layer on this disc, indicating not very good layer switching.

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.

Quite different from the previous reading, the drive managed to make quick work of the 545 test disc.

- Summary

Overall, good DVD error correction capabilities from the Plextor 755A drive with our test discs. Apart from the TDR 821 and TDV 541 discs, all other media were read at the maximum available speeds, indicating good error correction and generally good performance.