Disc Quality Results
Having recorded the maximum amount possible onto the Imation 16x DVD+R media at its rated recording speed of 16x to all available review drives with Nero CD-DVD Speed, the next stage of this review will concentrate on Disc Quality.
The first part of the Quality tests involved scanning all the pieces of Imation 16x DVD+R media recorded on each review recording device with the Plextor PX-760A Premium using Plextools XL Q-Check tests to find out how many potential SUM8 (PI Errors) and Sum1 (PI Failures) a playback device would have to correct whilst playing or transferring the recorded media. This also enabled me to obtain which of the 5 recorded pieces of media most matched the average result. The average disc shown below was then subjected to a Beta and Jitter test. Although more tests are available I believe I am showing the most common factors in overall disc quality.
"As the whole purpose of reviewing media for our readers is to try and obtain a good idea of the average quality of a given media, I have come up with this new methodology for determing these factors. These are my own personal views and by no means as accurate as an Industry C.A.T.S scan for measuring the quality of a disc but I believe I have come as close as I possibly can do with the equipment available to the average user."
I will expect that not every piece of media is capable of producing this
with such influences as excepted media/ hardware tolerance levels having an impact but I will expect the results not to consistently stray too far from set standards for a recommended media. It is also the sum of all tests that I use to determine the overall quality of the media and not one test alone.
The less Sum1 and Sum8 that are found on a media then in theory the better the chances are of good long term playback for this media without data loss becoming a significant problem. That's not to say that recordings with high Sum1 and Sum8 levels will be bad - the error correction logic of DVD playback and transfer devices are capable of correcting many potential errors. There is just more chance they might be affected by such influences as dirt or fingerprints. Different scanning devices scan slightly differently but basic guidelines using a Plextor drive are that Sum8 should not exceed 280 for sustained periods and Sum1 should not exceed 4 for sustained periods. You don't want to see any reported POF's (Parity Outer Failures) as these normally should result in uncorrectable errors!
Jitter and beta must remain within set specifications for a Plextor scan (Beta should not exceed +15 or -5 for sustained periods with the more level the result the better). Jitter should stay within the lower half of the graph for best results. Reading devices with good jitter correction ability should be able to read higher reported levels better than those that do not.
Overview of Disc Quality results:
It is clear to see that if the Plextor Q Check Quality tests are correct, that all recording devices delivered results which are well within the set specifications laid out for a workable recording with the Philips DVDR1660P1 delivering the most favorable overall results. All other used recording devices delivered good Sum 8 and Sum 1 results without delivering the same good level of Jitter and Beta. Although these results show not interfere with readability, they could do with improvement. Once again the Solidburn logic used in the Philips drive shows that there is good compensation for the slower recording time.
In the extra tests carried out on this media, I found that leaving Solidburn disabled for known media on the Philips DVDR1660P1 resulted in slightly higher reported Jitter values then when tested in this review under the default settings. You can expect a quicker recording time with Solidburn disabled but I recommend leaving it on for maximum quality.
With the Plextor PX-760A Premium, a new strategy was created in the Auto Strategy database using the full burn (destructive ) mode. This new strategy was then used to see if any improvement in speed or quality was noted. I found during these tests that using the default option of Auto Strategy set to Auto and Power record left on worked as well if not better than forcing the creation of a new one under present firmware. You could of course disable Auto Strategy and Power record altogether allowing you to attain sub 6 minute recording times with the Imation 16x DVD+R media but consistent good quality recordings cannot be guaranteed as the advanced logic of the drive is not fully utilized.
A new test for the Media reviews extra concerns the Lite-On SHM-165P6S, which now through Lite-On's Smartburn utility allows for a new extra logic called Hyper Tuning. This, like Solidburn and Auto Strategy, monitors the recording and adjusts it in real time. With Hyper tuning enabled you can expect better Jitter results although on this media the improvement was only slightly better. As this is a new logic, I would expect improvement in the future
"Please note that you will need a compatible drive for doing these scans such as the Plextor PX-760A Premium I have used in this review for making my decisions on the potential quality of this media. Other drives you could try include Imation, Lite-On, NU TECH and ASUS branded writers, but only the Plextor drives with Q check functions offer the full range of tests."
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