DVD+R verification by Ferra.ru: the elite 13

Currently, the most popular and faster 4x disks cost three to four times as expensive. In this situation, it is very important to quickly find the right way in the existing assortment and choose one-two brands whose products to buy in future. DVD recorders will soon be available in every home. Why? Because almost every new computer is equipped with either rewritable DVD drive, or with a combo DVD drive. Prices for DVD disks have dropped to almost that for CDs! Not all of them, though. Currently, the most popular and faster 4x disks cost three to four times as expensive. In this situation, it is very important to quickly find the right way in the existing assortment and choose one-two brands whose products to buy in future. That will save you millions of nerve cells! It is logical that an article like that on DVD+R should appear after tests of 4x DVD-R disks. So, having armed with renewed testing software and a heap of consumables we decided to arrange our own verification of DVD+R disks available on the Russian market. Without pretensions of completeness, we used as many as 13 disks, from brands to nonames, in the tests. The names of disks, codes of the manufacturers and forms of shipment are summed up in Table 1.Let's take a closer look at each disk. Description of DVD+R discsThe first in the list is the disk presented to us as ADM. By the look, it is a typical noname, just a blank disk without any drawings on. On the edges, there are runs of lacquer, with part of the blank turned, the other not. Such a non-uniformity of the edges results in DVD+R misbalance and may cause a strong vibration. Over the inner rim, the blank is marked as DVD+R4.7 GB 4X followed by a long number of the disk. Since there are no additional layers of paint, the disk is translucent. The results suggest that you shouldn't expect a long service life of the media.Disks brand-named A-Media are manufactured in India at a factory of Moser Baer company. At the same time, the produce undergoes quality control by Mirex. There is a dense layer of beige paint applied on the blank. Over the edges there are runs of lacquer, mostly turned.This disk is shipped in a full-length box, with the insert made in the blue-white color palette. So is the disk. The layer of paint is dense and uniform. The quality of the edges is high, there are few runs. A good media, to look at.The nice-looking box of full-colored drawing contains a no less good-looking disk of lilac color. But the layer of paint is not thick enough, and the disk is translucent. Poor impression is left by the edges of disk with a great number of large turned runs of lacquer.This disk is the most expensive of all the presented. You can judge about its level by the corporate style of the insert's appearance. The disk itself is also made strict but to a good taste, with a layer of mat color applied on top. On the disk edges on a small part, there are visible runs of lacquer. Upon a closer look at it, we found air bubbles inside the plastic by the boundaries of the inner rim. Fortunately, this artifact was not found in all disks of the series.The Imation disk is shipped in a full-length box with a bright insert. There is a thin mat sputtering applied on the disk surface. The edges of the disk are the same as in the Fujifilm - with a great number of turned lacquer runs.The name MBI of this disk is arbitrary because it is not supported by anything. Judging by the manufacturer's code, it is not MBI at all but Prodisc Technology. There are no additional layers of paint, with the edges mostly not turned. In fact, it is a cheap blank disk that implies respective requirements. The checkup showed that the disk supports recording speed 8x but sells as a 4x, for which there are reasons.The Memorex disk is shipped in a box with insert having the design customary for a brand. Over the upper side of the media, there is a dense mat coating. The edges of the blank are neatly turned. It leaves a good impression.The only disk that came to us in a slim box. The design of the blank disk is strict, in black and white colors. White mat color is used as an additional protective layer. In some places, there were lacquer runs found.The Smartbuy disk is made in bright coloring, although bright colors is not the most important thing. On the one hand, it is the insert where apart from others a trendy silver tint is used. On the other hand, the disk is white with mirror edging. At the same time, the mirror layer is not a substrate - two layers of paint are applied, which increases the reliability of data storage and improves the read/write quality. The edges are neatly turned.The Sony disk looks brighter due to the use of silvery and red colors in the design of the insert. The unusable side is covered with a thick layer of mat paint. There is a bright blue “Sony Corporation” stamp over the inner rim. Looks very much worthy of a brand. The outer edges of the disk are abundant with turned lacquer runs.The design of the TDK disk box is unchanged and easy to recognize. The blank itself is of pearl color. The paint layer is uniform but not very thick - the disk is translucent. The edges are turned, with the lacquer runs making a crest right in the middle of the disk.You can find a number of sorts of Verbatim disks on the market. That is Verbatim Digital Movie in a gift package, colored Verbatim Pastel and regular Verbatim Printable. The latter is just presented above. Despite that a drawing is to be applied on the surface, the existing layer of paint is dense enough. The edges can be regarded ideal because the lacquer runs are missing completely. Results for writing DVD+R disks To produce a more impartial view for writing disks, we decided to use two drives – Teac DV-W512G and LG GSA-4082B. The former is known for issues that come up when problem disks are used, and the latter - for its high writing quality. Further check of the media was done on both these two drives as well as on a Lite-În SOHC 5232K combo drive. For a start, we evaluate the time taken for writing a DVD+R. Since all the disks tested are meant for writing at 4x speed, the time taken for the process amounted to 14 minutes 30 seconds +/- 6 seconds. The exception is the ADM disk whose time of writing on a Teac drive amounted to 14 minutes 39 seconds. Note that the LG drive writes disks a bit faster than Teac does. Table 2 presents a detailed data on the time of writing.The next stage is testing the writing quality. For tests, we used two programs – CD-DVD Speed v. 3.40 and KProbe v. 2.3.0. We decided to confine with the following set of test tasks: 1. Checking all the disks for PI and PIF errors with KProbe on a Teac drive. 2. Checking all the disks for PI and PIF errors with the disk quality test being part of CD-DVD Speed, on a Lite-On combo drive. 3. Checking all the disks with the standard CD-DVD Speed test on a Lite-On drive (the read graph is estimated). Quality assessment criteria First of all, we should explain what the above parameters PI and PIF are. PI stands for Parity Inner, PIF – Parity Inner Failure. They both indicate the number of random errors registered while reading a media. The former indicates the number before correction, with the latter - afterwards. Where do they come from? Every 172 data bytes on the disk are equipped with a tail of 10 service bytes containing the information necessary for error correction, the PI. If at least one or two broken bytes are found, the PI can be used to completely restore the information. All the 182 bytes form 1 line. To increase the data storage reliability and improve correction, there go 16 service (PO - Parity Outer) bytes. Due to that, we can try restoring information. An aggregate of 208 lines is called an ECC block. A line in the ECC block in which at least 1 data byte was read with an error is regarded a PI error. The maximum number of errors in a ECC block is 208. In the tests, ECC blocks are normally united into a chain of 8 blocks. Therefore, the maximum number of PI errors is 1664. After correction, the number of errors is much smaller. The PO data helps restore data in the lines where the number of read bytes is no more than 5. Therefore, a line containing over 5 broken bytes is regarded fatal. That is just the PI Failure. The maximum number of PIF is also equal to 1664. There exists the ECMA standard for DVD+R/RW according to which one ECC block should have no more than 4 PIF errors, and in 8 consecutive ECC blocks the number of PI errors should be less than 280. It's just these criteria which we'll be guided while assessing the quality of disks. Primary tests The test result is affected simultaneously by both the disk quality and the drive quality. For the Teac drive, that means that the number of PI and PIF errors in using it as a test base will somehow exceed the value typical for the disk in general. Evidently, it doesn't make sense providing details of each media, so we'd better dwell on the most standard ones. To start with, here is a summary table on testing all the disks with a Teac drive.Judging by the results, the writing quality for a Teac drive leaves much to be desired. Nevertheless, most disks passed the first verification stage. The ADM blank disk proved to be the worst performer - its characteristics exceed the admissible despite the writing source. Besides it, Memorex, HP, Digitex, and A-Media failed to pass this test. The best were Imation, MBI, and TDK. All the graphs can be divided into the four main groups: repulsive quality over all the disk surface, reduced quality at the disk edges, a problem area in the beginning, and normal quality over all the disk. The Memorex disk written on a Teac drive whose PI and PIF error level was persistently at 1200! That means complete unreadability. The writing results for ADM on a Teac drive proved a bit better. From the very start, the error level was close to 1000, where the PIF level was not lower than 100. A similar picture is observed with Digitex disks, a bit better for A-Media disks written on a Teac drive: up to 800 and up to 400 PIF, respectively. The problem area at the start is seen in only the two graphs: for Fujifilm and Sony written on a Teac drive. The original peak was at 280 PI, and PI was no more than 10. These disks will be read on almost any drive without errors. Very good graphs may demonstrate the rise of error numbers towards the external tracks, but the PI level stays below 100 (40 on the average), where PIF is lower than 10 (3-4 on average). Among them are Fujifilm, Imation, MBI, Memorex, Philips, Sony, and Verbatim written on an LG drive, as well as Imation, MBI, and TDK written on a Teac drive. The remaining disks fell within a group where the quality gradually gets worse towards the disk edge and in most cases exceeds the norm. A typical example: the quality of an ADM disk written on an LG drive was persistently normal until somewhere at the middle of the disk, then the number of PI errors exceeded 200 per 8 blocks and reached 1010, and the PIF level was fixed at 191. The HP disk written on a LG drive stood out somehow. It demonstrated perfect values for errors, but at the last megabytes it demonstrated a sharp rise when the PI and PIF values jumped to 800. Note that single peaks with high performance present in each graph are related to noise and not taken into account. Repeated checkup Results of the previous tests showed that the quality of writing and reading on a Teac drive strongly affect the results. Therefore, we can't do without a repeated checkup with a side drive, in this case, Lite-On. So, here is a summary table for tests of all the disks with a Lite-On drive.At this test, the best disks are Fujifilm, Imation, MBI, Sony, and Verbatim. The worst are Memorex, Digitex, ADM, and TDK. The Digitex disc written on a Teac drive fell within the group of uniformly low quality. That is an evident mutual dislike. The PI level did not go lower than 400 and reached 1400 at the external edges. At the same time, the PIF level reached 57. Those which fell within the group of good graphs were A-Media, Fujifilm, Imation, MBI, Sony, TDK, and Verbatim disks written on a Teac drive, as well as A-Media, Fujifilm, Imation, MBI, Memorex, Smartbuy, Sony, and Verbatim written on an LG drive. Field test The last test is more of demonstrative character. Above, we talked about read errors most of which can be recovered. Standard tests with CD-DVD Speed will let us find out if the errors and problem areas which result in reduced disk read speed are recoverable. We should say that all the disks during tests proved readable, so formally we had no claims towards the manufacturers of the media. In the below table, the "+" sign means a smooth read graph, while the "-" means there are jumps of speed.The results is not bad indeed - merely three broken graphs. Let's take a closer look at them. for the ADM written with a Teac drive – the graph vividly shows small enough jumps at the external tracks. But on the whole, the result is good. For Memorex written with a Teac drive we can see that at the last 600 MB there appeared significant jumps from 8x to 6.4x. That is an evident problem area whose reading will get worse with time. For TDK written with a LG drive we can see that at the last 200 MB the read speed dropped 8x to 4.8x. That is an evident problem area on the external track. Summary It's high time we consolidated all the findings. Based on the first two tests, let's sort the disks as per the results of each test. They are 4 in each table, or 8 altogether (primary tests and repeated checkup). The last place taken means 0 score points, with 12 for the first place.What is left is just sum up the score points for each brand and declare the winners.Note that in the top five the upper two places are taken by disks of the manufacturer code Ricoh Company Limited, with the other two places taken by Mitsubishi Chemical Corporation. The MBI blank disk fell within the top five because it is originally aimed at 8x writing. Among the three outsiders is the ADM blank disk of which we did not expect much. But the other two proved a real surprise to us – the low-end Digitex, and the expensive HP. What to say to that? The market of optical disks if full of surprises. Finishing the verification, we should recall the GOST standards for PI and PIF errors. Let's look at the results of the first two tests to find out which disks meet the ECMA requirements.As you can see, again the same brands - Imation, Fujifilm, Verbatim, and MBI - passed the tests. Doesn't that remind you of so familiar names? Sony and A-Media proved a bit close to that, but they can be also recommended for permanent use. ADM, Digitex, and HP failed to pass three tests of four. They can be used of course, but don't expect a long service life from them. The totals have been summed up, graphs and tables shown, our opinion pronounced. It is now up to you to decide.