detail information

The specifications of this drive tell us that it should write DVD+R discs at 16x and DVD-R discs at 8X. In this part we will measure the write time for various types of DVD-/+R discs. We 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 F16 uses CAV, (Constant Angular Velocity) to write DVD+R at 16X.

8X DVD-R Writing speed:

The Memorex F16 uses Z-CLV, (Zone-Constant Linear Velocity) to write at DVD-R at 8X. Let us compare these to the write technologies used by some other drives:

The Pioneer DVR-A08XLA uses Z-CLV, (Zone-Constant Linear Velocity) to write to DVD+R and DVD-R discs at 16x. The above image shows a DVD-R disc written at 16x.

The BenQ DW1620 uses CAV (Constant Angular Velocity) to write at 16x. The dips that you see in the graph are caused by the BenQs' Walking OPC technology, which is used to improve burn quality. The above image shows a 16x DVD+R disc written at 16x.

Next we will test and measure the time for writing to DVD-R and DVD+R discs within Nero. We used Nero burning Rom to burn an ISO compilation containing 4483MB of data. We used the Disc-At-Once write method.

DVD+R test burn

DVD-R test burn

How does the Memorex F16 compare to other writers on the market? We have built a table to analyze these write times. Please reference below for comparisons:

*Actual writing speed was 12X in these areas for the Pioneer A08.

As we can see, the Memorex F16 is about average for 16X speed DVD+R writing. It is the slowest DVD-R writer due to the 8X maximum write speed limitation.

Please note that the Memorex F16 uses a P-CAV (Partial-Constant Angular Velocity) write method when burning DVD+R at 8X, which allows for a much faster 8X DVD+R writing time when compared to other writers.

A more important question would be; 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!

Write quality:

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, as already said; 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.

Please note that the example scans below were performed with an older version of Kprobe. In this older version, PIF is mistakenly labelled as 'PO".

This scan shows the results from a pressed DVD-ROM disc (Baldurs Gate DVD-ROM).

This scan shows the result from a pressed DVD-Video disk (Indiana Jones and the last crusade). Notice the error jump when shifting to the second layer (the error level actually drops from the end of the first layer to the beginning of the second layer).

If you read below you will see that both 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 (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 do not copy and paste everything but if interested 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 is over 300 and most players starts 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 are what 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.

And another 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 Mad Dog MD-16XDVD9 DVD-Writer. A small speed reduction near the end 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 wondering what to look for in Kprobe reports?

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 clean 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:

The Kprobe scan and the reading curve are both acceptable here. What do you know? Memorex brand media will work fine with the Memorex F16 DVD writer.

The PI levels are higher than what we would have liked, but the read-back curve is acceptable and the disc was fully readable. We tested with multiple MCC004 discs and the results were all similar. We believe the writing strategy for this media type may need some improvement.

PI and PIF error levels are all within acceptable ranges, but this is far from the best results we've seen with this media. The read-back curve had some slight problems but this is nothing major as the disc was fully readable. We would also like to see this media supported at 16X since many of the competing writers on the market already have the capability to write this media at higher speeds.

The PI/PIF results are perfect here, but the CD-Speed test showed some reading problems. Overall it is a fair result and it unlikely that you should have any major problems with this media.