X-bit labs

Ultimate Testing of Recordable DVD Media Discs (page 24)

Category: Storage

by Andrey Kuznetcov

[ 04/14/2005 | 08:08 PM ]

Conclusion

We have already said a few words on each of the participating discs, but now we will try to make some generalizations. There’s a pragmatic problem before each user: are you guaranteed to have high burn quality if you purchase media from brand names only. We can reword it this way: is it possible to find good media at low price? We guess this test session has helped to answer this question: expensive media are not necessarily the best ones as concerns quality. A renowned brand does not give you any warranty here – you can have the same problems with an expensive brand-name disc as you do with cheap discs from obscure companies. Considering that discs selling under different brand are often a product from the same manufacturer, it is the more reasonable to choose the one that costs less. You don’t want to shell out more just for the brand, do you?

For an easier reading of the results of the tests, we created summary tables that include all the reviewed discs divided into categories by their format. For better readability, if the maximums of errors of both types fit within the acceptable range as described by the industry standards, the disc is highlighted with blue (click the tables to enlarge and see more details). To make the tables even more informative, we highlight the discs that are approved by both programs as having appropriate PI error and failure parameters with green. If this successful result is achieved in one program only – the disc is highlighted with yellow. Blanks of these two colors should provoke no problems in use. Discs that couldn’t pass the quality test in neither of the programs are highlighted with orange. With this rather formalistic approach some discs suffer because of their having single spikes of errors but are otherwise quite compliant with the requirements. Such discs should also be considered as quality ones, but you have to refer to their particular diagrams to agree or disagree with that. We personally think that orange is a kind of warning that there may be possible problems with such media. And lastly, the discs without any of the colors are media that our test drive couldn’t burn at all. There are three such discs, two of which are actually twins, selling under different brands. As we said earlier, this incompatibility may be eliminated in the next firmware update for the Lite-On drive.

As for the two programs, the two test tools that we used in our tests, Nero CD-DVD Speed and KProbe yield very similar results in most cases, but sometimes they do disagree. CD-DVD Speed is a more universal tool, but sometimes it freezes during the scanning of problem discs or refuses to work with them at all. KProbe is originally intended for optical drives manufactured by Lite-On (drives on Mediatek chipsets), which limits its scope somewhat. Sometimes it has problems with DVD±RW discs when it wrongly determines the boundaries of the recorded area in the automatic mode and starts to throw messages about servo-errors at you. This can in some cases be cured by a preliminary reformatting (erasing) of the disc. Otherwise, you have to identify the test range with an LBA address which you must provide. This is not quite convenient if you want to check out just a single rewritable DVD disc and do not know the exact spot where the recording ends. Thus, it’s hard to tell which of the two programs is better. Each has its own pros and cons.

In this review we didn’t cover such issues as the time the written information is retained on the disc and the ability of the rewritable discs to keep their quality up after numerous write/erase cycles. We hope you understand why – such tests would just take too much time. Another disturbing question for any user is how the burn quality depends on the burn speed. Many people hold the opinion that the data transfer to the medium can only improve at reduced burn speeds, so the quality is the best at the minimal speeds. We think this is an intriguing topic for discussion and we are going to deal with it in one of our upcoming reviews.

The last thing we want to remind you is that the results we got in our tests are true for the particular conditions described in the Testbed and Methods section and may be different if the discs are written in other optical drives or in different burn modes.