In the following tests, we check the DVD reading capabilities of the BenQ DW1655 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.

The reading speed maxed out at just above 8X, which is a little slow. Also notice that at the beginning, the speed ranged between 6X and 3.5X before eventually beginning the reading process.

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.

In this case, the drive read all the way to the end of the test without any errors, while after the second defective area, the reading speed maxed out at 14X, with minor jumps down to 6.5X.

- 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 were read flawlessly, reaching a max speed of 12X, while a small speed drop was noticed over the last part of the defects region on both layers.

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.

The drive successfully completed reading both layers, passing over all four artificially defective areas, without any drops in speed or errors being 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.

Even though the drive managed to complete its reading of the 541 test media, the reading was not stable all the way to the end with a few problems during the last stage of the first layer and just after the layer switch.

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.

With the 545 test disc, the drive did not present any problems, successfully reading all the way to the end of the test.

- Summary

Even though the DVD error correction tests reported no errors whatsoever, the performance of the drive was not excellent, as one can clearly see from the drops or deviations in speed during most of the tests. None the less, the drive will read over defective areas, even though this may be to lower reading speeds.