detail information

The specifications of this drive tell us that it should write both DVD+R and DVD-R discs at 16x. In this portion of the review we will measure the write time for various types of DVD-/+R discs. We will also focus on write quality and media compatibility.

DVD-Writing performance:

First, we shall take a look at the writing technology used for DVD+R and DVD-R writing.

16X DVD+R Writing speed:

The Memorex DVD+/-RWN16 D2 uses CAV (Constant Angular Velocity) to write DVD+R at 16x. This gives an average writing speed of 11.76x and a total write time of 5 minutes and 54 seconds. The drive also uses NEC's Active OPC technology when writing (shown as small dips in the transfer curve above), which helps to improve burn quality. The disc written here is a PHILIPSC16 16x DVD+R.

16X DVD-R Writing speed:

The Memorex DVD+/-RWN16 D2 also uses CAV (Constant Angular Velocity) to write DVD-R at 16x. This gives an average writing speed of 11.73x and a total write time of 5 minutes and 42 seconds. The disc written here is an MCC03RG20 16x DVD-R.

Let us compare with some other drives.

The ASUS DRW-1604P uses Z-CLV, (Zone-Constant Angular Velocity) to write DVD+R at 16X. This gives an average write speed of 10.29x and a total burn time of 6 minutes and 48 seconds.

The Toshiba SD-R5372 uses CAV (Constant Angular Velocity) to write at 16x speed. This gives an average speed of 11.74x and a total writing time of 5 minutes and 43 seconds.

We can see that the Memorex drive is faster than the ASUS DVD writer, but a one second slower than the Toshiba DVD writer. Let us compare the writing time statistics to a larger pool of DVD writers in the table below.

*Actual writing time was only 12x for the Pioneer DVR-A08XLA on 16x DVD+R.

Taking a look at the table, we can see that the Memorex drive can stay head to head with many other drives in the DVD writing speed arena, especially with 16x DVD-R writing.

We also tested 16x burning while connected to the Firewire (IEEE 1394) interface.

AMD CPU system

Intel CPU system

Unfortunately we encountered issues burning at full 16x speed when connected with the Firewire (IEEE 1394) interface. We tried on four different computers using two different types of Firewire cards (Texas Instruments Firewire controller and VIA Firewire controller) and the results were similar. Intel CPU based systems definitely performed better, but they still had trouble reaching full 16x writing speed on the Firewire interface. Strangely enough, 16x DVD±R reading works perfectly on the Firewire connection.

A more important question is; how is the DVD±R/RW write quality of this drive? After all, you do want to be able to produce discs that are readable and useful. Let us find out now!

You should first take note that this is not a scientific and professional way to test the discs. But according to our testing done in the past, we would conclude that there is a clear link between the quality reported when scanning the disc and the playability of the disc in different devices. Also notice that different drives report different amounts of errors. K-Probe was designed to work with Lite-On DVD-Writers. So we recommend using a DVD-Writer from Lite-On. In these tests we use a Lite-On SOHW-1633S DVD-Writer. Remember that scans done with a Lite-On DVD-ROM or Lite-On combo drive can't be compared with the results obtained with a Lite-On DVD-Writer. Also remember that different PI/PIF ECC sum settings along with different reading speeds in K-Probe will affect the result, we use these settings;  PI (Parity Inner) set to summarize 8 ECC blocks, PIF (Parity Inner Failueres) set to summarize 1 ECC block, reading speed: 4X CLV (Constant Linear Velocity). Setting the PI sum to 8 and the PIF sum to 1 will give a result that we may compare to the standards for DVD+R/RW and DVD-R/RW.

But what is a good scan? That is a discussion that we don't think will end soon. This is due to the fact that different drives report different amounts of errors, some players are more picky about media than others and many other factors. For comparison purposes we present you with a scan from two pressed DVD discs.

This scan below shows the results from a pressed, Single Layer DVD-Video disc (Ronin DVD).

This next scan shows the result from a pressed Double Layer DVD-Video disc (Lord of the Rings, The Return of the King). Notice the error jump when shifting to the second layer (the error levels actually drop from the end of the first layer to the beginning of the second layer).

If you read below you will see that both of the pressed DVD-discs are well within the standards.

Download the ECMA 267 Standard for DVD-ROM, the ECMA 337 Standard for DVD+R/RW and the ECMA 338 Standard for DVD-R/RW at http://www.ecma-international.org if you want to look at the standards for yourself. Here is some data from the ECMA standards (it is the same for DVD-ROM, DVD-R/RW and DVD+R/RW):

Random errors:

A row of an ECC Block that has at least 1 byte in error constitutes a PI error. In any 8
consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280.

Here we see what a PI error is defined as a row in an ECC block having 1 byte or more containing errors. And that the sum of PI errors in 8 ECC blocks after each other should not exceed 280 PI errors.

But what is a row and what is an ECC block? Again we refer to the ECMA standards. We did not copy and paste everything but if you are interested in further details, please look in the ECMA standards. A row is 182 bytes long where the last 10 bytes contain PI (Parity Inner) information. An ECC block is 208 rows long where the last 16 rows contain the PO (Parity Outer) information. This gives us a maximum possible PI error amount of 208 errors per block and for 8 blocks after each other this sum is of course 8 times higher giving a maximum possible amount of 1664 PI-8 errors. In practical use a disc with 1664 PI-8 errors is unreadable.

According to our tests the specified max PI-8 sum of 280 for good discs seems to be a good guideline, as some readers have problems reading discs when the PI-8 errors are over 300 and most players start to have problems when the PI-8 error level reaches 600 or more.

But what are the PIF errors that K-Probe reports? They are Parity Inner Failures, meaning errors left after PI correction. Only the ECMA 337 standard describes the Parity Inner Failures. So how is a Parity Inner Failure defined? Here is what the ECMA 337 states:

'If a row of an ECC Block as defined in 13.3 contains more than 5 erroneous bytes, the row is said to be 'PI-uncorrectable"."

In theory an ECC block may in the worst case have 208 PIF since every ECC block is 208 rows long. But the ECMA 337 standard goes further and specifies the max amount of accepted PI Failures (uncorrectable errors) allowed on a good disc:

'- In any ECC Block the number of PI-uncorrectable rows should not exceed 4."  

This means that when the PIF sum is set to 1 the maximum error value should not exceed 4. The theoretical maximum value for PIF is 208 errors.

But what makes a disc unreadable? A POF (Parity Outer Failure) error will make the disc unreadable, but K-Probe does not display the POF's.

Notice that there are other aspects such as disc reflectivity, jitter, tracking errors and so on that also will affect the readability of a DVD disc - but for this we do not have measuring equipment available.

Another detail to note is that we have scanned the discs at 4X CLV speed, by lowering the speed to 2X(DVD-R/RW)/2.4X(DVD+R/RW) or 1X the amount of reported errors may drop on some discs. We use the 4X CLV scan speed for all of our PI/PIF tests.

To see if there is a connection between the reported amount of errors and readability of the discs, we also include a transfer rate test reading curve from the NEC ND-3500A DVD-Writer. A small speed reduction near the end of the reading curve is still accepted on good discs, but serious reading problems or reading failures is a bad sign.

Easier explanation on how to read the test results.

Maybe this got too technical, and you are just wondering what to look for in a Kprobe graph?

Use this as a guideline for good discs:

PI (Parity Inner): No larger areas on the disc should exceed 280 PI-8 errors, do not worry too much about high single spikes that exceed 280. Lower error levels are always better.
PIF (Parity Inner Failures): No larger areas on the disc should exceed 4 PIF-1 errors, do not worry too much about high single spikes that exceed 4. Lower error levels are always better.

What about the reading curve? If the graph looks smooth with no dips then the disc should be very good. A small slowdown near the end is acceptable.

DVD+R media compatibility and write quality:

There are a few solitary PIF spikes in the Kprobe scan, but the averages look good and the reading curve also looks good. Overall, a good result!

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Of course the Memorex drive supports Memorex 16x DVD+R at the correct speed. The result is good.

The Kprobe results look relatively good here, the couple of irregular PIF spikes shouldn't be too concerning. The transfer rate test looks good. Good result!

A few PI/PIF spikes grab our attention, but the averages are good and the reading curve is near perfect. A good result!

Good results here on high quality Taiyo Yuden DVD+R. These 8x certified discs were burnt at 16x. A few solitary PIF spikes show up, but it is not anything to be too worried about. The reading curve looks good.

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High Quality Maxell DVD+R made in Japan burned very well on this drive. We can easily recommend this media.

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Another stunning result with RiDATA 8x DVD+R.

Here we obtained near perfect results with 8x Verbatim DVD+R media. We can absolutely recommend these discs.

Simply excellent Kprobe results! We expected the Memorex drive to perform well with Memorex media and we were not disappointed! The reading curve has a small slowdown near the end but it is nothing too major to worry about.

 DVD+RW media compatibility and write quality:

The specifications of the Memorex DVD+/-RWN16 D2 state that it supports DVD+RW at 4x. Here we will test with a few types of DVD+RW media for speed and quality.

Excellent speed and quality! Highly recommended DVD+RW media.

PI/PIF results are not as good as the RICOHJPNW11 discs, but these results are still okay. The reading curve is near perfect. We have seen much worse results on this same media. 

Great results on Memorex DVD+RW media manufactured by Infodisc! 

DVD+R/RW Performance Summary: The DVD+R/RW compatibility is near perfect. All of the tested discs were able to be written at the certified speed or higher. Some 8x certified discs can be written at 16x, which is a very nice feature. DVD+R/RW writing quality was also very good.  Excellent job here Memorex! It is good to see a drive that excels in both media compatibility and writing quality.

Head on to next page and read about DVD-R/RW compatibility and write quality...