by Andrey Kuznetcov
12/20/2006 | 12:35 PM
There are no extraordinary traits about the appearance of the device. However, the manufacturer has done something to “enliven” it visually. There is a horizontal line going along the disc tray below the manufacturer’s and model names. Under the tray there is a rounded eject button and a LED indicator of operation mode. Next to them there are a few icons denoting the class and technical features of the device. The rear panel of the drive carries power and interface connectors, a jumper with pins to select the status of the device on the IDE channel, analog and digital audio outputs. There are also vent openings in that panel.
The drive can read DVD-ROM media at 16x speed and CD-ROM media at 48x speed, but the CD read speed is limited to 40x by default to reduce noise. You should use the PlexTools software to enable the highest possible speed. DVD+R and DVD-R can be recorded at 18x. DVD+RW and DVD-RW media can be written at 8x and 6x, respectively. The max burn speed for DVD+R DL and DVD-R DL formats is 10x and 6x. CD-R and CD-RW discs can be recorded by the drive at 48x and 24x, respectively.
The average access time is 100 milliseconds for CD and 150 milliseconds for DVD media. The cache buffer is 2MB large. The drive is equipped with an EIDE (ATAPI) interface and supports the following media formats: DVD-ROM, DVD-Video, Multi-Border, Multi-Session, DVD+VR, DVD-VR, DVD+MRW (by firmware upgrade), DRT-DM, CD-DA (CD-DA/CD+G/CD-Text), CD-ROM (Mode1/Mode2), CD-ROM XA (Mode2 Form1/2), Audio CD, Data CD, Photo CD, Video CD, CD-I, CD-I Ready, Mixed CD, CD-Extra, Multi-Session CD, Packet Write CD (Mount Rainier by firmware upgrade), Bootable CD. The dimensions of the drive are 146x41.3x170mm; its weight is 1kg.
Just like every other product from Plextor, the optical drive features a number of innovative technologies. In this model, it is the Autostrategy feature that is the most important. The point of this technology is to choose the optimal burn strategy for each DVD disc. And it is possible to create new burn strategies for unknown media (recordable DVDs) that are missing in the firmware database. The drive’s memory can store up to 31 strategies. New burn strategies can be enabled/disabled and removed. You can view, save or print the list of new burn strategies. Besides that, the drive supports Media Quality Check, Write strategy creation, PlexEraser, SecureRecording, Buffer underrun proof, Silent mode, SpeedRead, GigaRec, VariRec, Q-Check, PoweRec, and PlexTools Professional (XL) technologies. The last one deserves a special mention.
The PlexTools Professional (XL) software allows to enable the mentioned innovations to achieve the best possible burn quality on a majority of media types. We’ve already described the capabilities of this program and the other technologies in our previous Plextor review.
The PX-760A drive comes with a software CD (its contents are shown in the screenshots above), a black faceplate, installation instructions, and an IDE cable. The average retail price of the drive is $107.
The following programs were used to test the optical drive:
The testbed was configured like follows:
We tested the drive in the same way as it would be selling, without any modifications. We attached it as Master to the second IDE channel.
These two informational utilities report the hardware characteristics of the optical drive.
There are two screenshots of the Nero Info Tool program to remind you that the CD read speed is set at 40x by default and you can increase it with the appropriate setting of the PlexTools Professional suite. The drive is reported to support almost all the hardware features that most people use regularly. The only feature that is missing is the ability to work with DVD-RAM media.
I tested the drives in CD WinBench 99 using a molded CD-ROM and two copies of it made on CD-R and CD-RW discs. This will help us see how the drive processes different types of media.
These data-transfer graphs show that the drive has no problems at reading the media with the exception of the CD-R whose graph has a small jagged section at the beginning.
The drive shows its highest performance with the CD-ROM and lowest with the CD-RW. The tests of read speed produce expectable results: this speed is the highest with the CD-ROM and the lowest with the CD-RW. The measured access time is not bigger than the declared value. It is the lowest with the CD-R and the biggest with the CD-RW disc.
I use five CD media to perform these tests: a molded CD-ROM enclosed with a magazine, 700MB data CD-R and CD-RW discs recorded by Nero CD-DVD Speed itself, a likewise prepared 800MB CD-R, and an Audio CD.
The drive refused to read not only the 800MB CD-R, which is not a rare thing in my tests, but also the standard-size CD-R. This brings the new version of Nero CD-DVD Speed (4.60) under suspicion as I’ve never encountered this problem before. The diagrams don’t give me any reason to criticize the drive.
Here, we can see that the real speed limit for CD-RW and CD-DA media is about 40x instead of 48x. The measured access time is somewhat higher than the specified 100 milliseconds (for CDs). But the specification probably refers to CD-ROM whereas the access time is usually a little higher with other media types.
The second group of tests is about DVD media. I took eight discs to get a fuller picture of performance of the drive: a DVD-ROM with a video movie and its copies made on DVD-R (Digitex), DVD-RW (TDK), DVD+R (Fujifilm), and DVD+RW (Verbatim) discs. I also used a dual-layer DVD+R from RIDATA and a dual-layer DVD-R from Verbatim.
Take a look at the read speed diagrams first. The data-transfer graphs do not indicate any problems.
Speaking in general, this optical drive is up to its own specification. It provides a max read speed of 8x for dual-layer media and of 12x for DVD+R, DVD-R, DVD+RW and DVD-RW formats. The measured access type is not bigger than the specified value with any type of the medium.
The Advanced DAE Quality Test helps determine hardware characteristics of an optical drive pertaining to the process of getting accurate copies of CD-DA media. Two CD-R discs prepared in Nero CD-DVD Speed are used in this test. One audio disc is normal; the other has defects of the surface, imitating your trying to make a copy from a long-used, bad-quality audio compact-disc.
The drive is blameless in this test. It has a 100% quality score, can read all types of auxiliary information, and has a moderate offset at reading (this parameter indicates how accurately the drive can position on a given spot of an audio disc).
The second screenshot shows the drive processing the bad-quality disc. It had some problems here and didn’t complete the test. But even before the moment it hung up, the drive’s read speed had declined greatly and there were a lot of errors.
The ability of an optical drive to process C2 errors and to process them efficiently is most important when it works with low-quality media. I ran the Advanced DAE Error Correction test with the bad Audio CD prepared in Nero CD-DVD Speed to check the drive’s ability to process errors that occur during the audio ripping process. The problem is that even if an optical drive can process C2 errors, it may not do that satisfactorily. So, the program determines how many C2 errors should be found by the drive and how many errors the drive actually finds and then produces C2 Accuracy and Quality Score parameters which reflect the efficiency of the hardware error-correction logic in the given drive. Unlike the previous test, this one not only tells how many errors occur as the drive is reading an audio CD, but also evaluates the drive’s ability to find such errors.
The drive doesn’t look too good in this test. Its error-finding ability isn’t perfect. Judging by the numbers, it only finds one out of each three C2 errors.
I used two programs to measure the drive’s speed at extracting audio tracks. The first one is Nero CD DAE, which was developed quite a long time ago, but is still up to users’ requirements. This program’s algorithm is simple and doesn’t make wide use of some of hardware characteristics of the drive – this is the algorithm many other programs of this class stick to. I used the Nero CD DAE utility to estimate the speed it took the drive to extract audio tracks from the audio disc I had used earlier and to convert them into WAV-files. I enabled the option of double reading of each track to look for errors.
The drive worked at its highest speed (for this type of the medium) and didn’t make a single error.
The second audio extraction utility, Exact Audio Copy, differs from Nero CD DAE as it is capable of making use of the hardware characteristics of optical drives to achieve the maximum quality of the resulting files. I used the EAC utility to determine the hardware properties of the drive (using the Drive Options menu) and then to extract audio tracks (in the Secure Mode) from the same disc as in the previous test; the tracks were saved as WAV-files.
To check out the support of C2 errors, a special “bad” audio disc was used, prepared by Nero CD-DVD Speed.
So, the drive supports the data caching and Accurate Stream features and can process C2 errors. The data caching isn’t good for creating accurate copies of Audio CDs. The drive spent more time for this test than for the previous one, but there are no errors again.
As the final step in this test session, I will burn a few DVD discs of various formats in the tested drive and will check their quality. Of course, I can’t check the drive with all existing media, in all possible modes and at all supported speeds, but this test is anyway indicative of the burn quality the optical drive provides. I used Nero Burning Rom to record all the discs at their maximum rated speed. The quality of the recorded discs was verified in a Sony DW-G120A drive with MYR4 firmware. We use it to achieve comparable results from different test sessions, and this drive offers good hardware characteristics for that purpose.
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 you should keep it in mind that besides the hardware properties of the drive, its firmware version has a big effect on the burn quality, too. Some problems can be solved by the manufacturer with firmware updates.
The quality of this disc doesn’t meet the ECMA requirements. The maximum of PI Errors is all right, but the allowable maximum of PI Failures is exceeded in several places here, although without any regularity. The total of errors is not large.
If I were formalistic, I would find fault with the Digitex DVD+R as there is one place in the diagram where the maximum of PI Failures is higher than permitted by ECMA. This is not a big problem, though, so the overall burn quality of this disc should be considered as very good.
Certain problems can be seen with this Philips DVD+R disc. The level of PI Failures is higher than normal, especially on the final part of the disc. The disc meets the ECMA requirements in terms of maximum allowable level of PI Errors, yet the level of such errors is high on this disc.
The Sony DVD+R doesn’t meet the ECMA requirements as the maximum of PI Errors exceeds the permissible limit. The final section of the disc is especially poor in this respect.
The Verbatim DVD+R isn’t blameless from the ECMA standpoint as there is a spike of PI Failures above the allowable maximum. The burn quality degenerates at the end of the disc.
The Digitex DVD-R cannot be criticized as the level of errors of both types fits within the ECMA requirements. The errors are also quite evenly distributed along the disc.
This DVD-R disc from LG is recorded with excellent quality, in full compliance with the ECMA requirements for both types of errors. The errors are very uniformly distributed along the surface of the disc.
There can’t be any complaints about the quality of this Sony DVD-R. There’s a low level of errors of both types, and the errors are also uniformly distributed along the disc.
The quality of this DVD-R disc is satisfactory. There’s a single spike of PI Failures above the allowable maximum, but the overall quality is acceptable.
The maximums of errors are not only within the ECMA limits but much lower than them. You should also note how evenly the errors are distributed along the disc surface.
I had to digress from our test methodology to check the quality of this disc. Nero CD-DVD Speed would report that the drive didn’t support that function, which was nonsense. I then tried to use the previous version of the utility (4.51.1) and it did everything right. The disc proved to be of excellent quality, fully compliant with the ECMA norms. It also has a very low level of PI Failures and a very small total of them.
This DVD+RW from Fujitsu doesn’t comply with the ECMA norms when it comes to the allowable maximum of PI Errors. Well, I should confess that many other optical drives have done no better with this medium. This is the case when the drive is limited by the quality of the medium itself.
Alas, the Philips DVD+RW disc that had been recorded well by many other drives betrays poor burn quality here. The maximums of errors of both types are higher than acceptable. The beginning of the disc is especially bad.
The quality of Digitex DVD-RW disc doesn’t meet the ECMA requirements. The maximum of PI Failures is above the norm. I suspect it’s not the drive’s, but the disc’s fault, though.
This DVD-RW disc is recorded with high quality. It complies with the ECMA requirements for both types of errors. I might say that its quality is typical of good recordable discs rather than of rewritable ones.
The key feature of the Plextor PX-760A optical drive is its ability to burn DVD+R and DVD-R media at 18x speed. Like every other product from Plextor, it supports a number of exclusive technologies that ensure optimal burn quality for almost every medium, including those that are not in the firmware’s database. The drive’s hardware parameters provide an opportunity to make accurate copies of Audio CDs. The drive recorded most of the test media with high quality (it is just impossible to produce a good-quality disc in case the quality of the medium itself is low). The retail version of the Plextor PX-760A comes with good accessories and the PlexTools utility gives the user flexible control over the drive’s operation modes.
On the downside is the not-very-confident processing of errors and the traditionally high price. I guess it only makes sense to spend over $100 for an optical drive if you are indeed going to utilize all of its special features besides the standard ones. Otherwise, you can buy an optical drive from a less renowned firm and spend three times less money!