Performance in Nero CD-DVD Speed: Disk Quality Test
As the final step in this test session, I will burn a few DVD discs of various formats in the tested drive and check their quality. Of course, I can’t check the drive with all existing media and in all possible modes, but this test is anyway indicative of the burn quality the drive provides. I used Nero Burning Rom to record all the discs at their maximum rated speed (except for some situations mentioned below). The quality of the recorded discs was verified using a Lite-On SOHW-1653S drive with firmware CS0T. We traditionally use it to achieve comparable results from different test sessions.
As for the disc quality criteria, the ECMA standards for DVD-R/RW and DVD+R/RW media say that the total number of PI errors in 8 subsequent ECC blocks should not exceed 280. This is the first limiting value I will base my judgments upon. Then, an ECC block should not contain more than four irrecoverable PI errors (an irrecoverable PI error is referred to as PI failure by the CD-DVD Speed utility).
DVD discs that have no more than 280 PI errors per eight ECC blocks and 4 PI failures per one ECC block should be considered acceptable-quality media. Besides these criteria, you should also note how the errors are distributed along the surface of the disc. It is the worst situation when the errors exceed the acceptable limit on the entire surface, but single and short-time spikes of errors are less dangerous.
Of course, the more discs are recorded with high quality, the better for the tested drive, but keep it also in mind that besides the hardware properties of the drive, its firmware version has a big effect on the burn quality, too.
Sony DVD+R 16x
Sony’s DVD+R disc rated for 16x burn speed could only be recorded by the Plextor PX-750UF at 4x. Of course, this affected the quality of the resulting disc, which is more than satisfactory. The low peaks of errors of both types and the manner of their distribution on the medium indicate this. The result would be different, of course, if the drive had burned the disc at 16x.
TDK DVD+R 16x
Only a very carping person would find any faults with the quality of the TDK DVD+R which I recorded in the Plextor PX-750UF drive. The maximums of errors of both types, and especially of PI Failures, fit well within the limits described by the ECMA regulations. The burn quality is uniform throughout the entire disc, so this is almost an ideal disc. It will surely be readable in any optical drive.
Verbatim DVD+R 16x
We get different results with this recordable DVD from Verbatim. It’s all quite well on the first half of the disc, but the other half brings about a sudden surge of errors of both types. The level of PI Errors exceeds the ECMA limit then, so the disc can’t be considered as a quality one.