DVD Error Correction Tests

In the following tests we examined the DVD reading capabilities of the external Freecom drive with scratched / defective DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed. The reference test media come 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 picture comes from the CDVD Benchmark v1.21 transfer rate test.

The drive read the contents of the 821 test disc without reporting any reading error. There were no speed deviations throughout 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, with the difference that there are no scratches on the surface and instead defective areas ranging in dimensions from 0.5 to 1.1 mm. There are also fingerprints with height between 65 and 75 micrometers.

The 825 test disc was more difficult for the Freecom drive to read. The drive had to slow down speed from 9x to 5x, a little before the second defective area on the disc. Once again the test ended successfully.

- 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.

No problems during the reading process of the 841 dual layer DVD-ROM. The drive read both layers accurately under CAV reading strategy and finished the test with an end speed at 9x

ABEX TDR-845

This disc is a single sided, dual layer DVD-ROM disc with capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 is that the first includes both defective areas and fingerprints. The dimensions of the defective areas range from 0.5 to 1.1 mm and the fingerprints have height sized from 65 to 75 microns (micrometers).

The drive needed momentarily to slow down during the reading process just before the artificial fingerprints on the first layer, but the test continued normally and finished without reading errors.

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 sized from 0.4 to 3.0 mm.

Nero CDSpeed shows that the Freecom Fx-50 found it difficult to finish the 541 test disc. The problem for the drive occurred after the layer switch operation where the drive needed about 700mb of the disc reading surface to regain a constant reading speed.

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer Video/S-2 disc with a capacity of 8.5GB. The TDV-545 includes artificial black dots on the disc's surface, sized from 0.4 to 1.0 mm. It also has 65 - 75 micrometer high fingerprints

Same performance as with the previous tested media for the Freecom drive, where again it needed some time after the layer switch to regain its feet.