LG GSA-4120B DL Recorder - Page 4
DVD Error Correction Tests
In the following tests we examined the DVD reading capabilities of the 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 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 can read DVD media up to 10X. The scratched area did
not affect the reading process. The LG drive showed very good behaviour
with this disc, and no errors were produced.
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 defective
areas of dimensions ranging from 0.5 to 1.1 mm.

There are also fingerprints sized between 65 and 75 micrometers.

Again, the drive didn't have problems reading this test disc. We can see
that the line is continuous, a little dense but the defects did not produce
any anomalies.
- 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.
. 

As seen above, once again the drive did not encounter any problems
reading this test disc.
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 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.

As is evident from the screenshot above, the drive lowered its
reading speed when it entered the area where the test disc includes the scratch.
Despite
this,
the
drive
finished its reading process without any problems.
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 disc's surface, sized
from 0.4 to 1.0 mm. It also has 65 - 75 micrometer thickness, fingerprints.

No problems here for the drive, a perfect curve with good performance.