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The specifications of this drive tell us that it should write DVD+R discs at 16x and DVD-R discs at 16X speed. In this part we will measure the write time for various types of DVD+/-R(W) discs. We do also focus on write quality and media compatibility.

DVD-Writing performance:

We will start with taking a look at the writing strategy used and compare it to other drives;

The Pioneer DVR-A08XLA uses Z-CLV, (Zone-Constant Linear Velocity). The first zone from 0-0,4Gb is done at 6x speed; the next zone from 0,4Gb to 1,9Gb is done at 8x speed, next zone from 1,9Gb to 4,0Gb at 12x and the last zone from 4,0Gb to 4,4Gb at 16x. This gives an average speed of 10.33x and a total writing time of 6m:42s. Notice that this is the only disc we were able to write at 16x. All other discs was 12x max - even if they should be supported at 16x.

The above image shows an 16x DVD+R disc written at 16x.

The BenQ DW1620 uses CAV (Constant Angular Velocity) to write at 16x. This gives an average writing speed of 11.51x and the lowest time we have obtained are 5 minutes and 47 seconds. The drive uses a bit longer time than ideal since it uses OPC technology when writing (shown as small dips in the transfer curve above).

The NEC ND-3500AG uses CAV (Constant Angular Velocity) to write at 16x. The average speed for the NEC ND-3500AG is 11.70x and total writing time is 6 minutes and 4 seconds.

Let us see how long time it needs to create a disc with Nero. We used Nero burning Rom to set up a new UDF/ISO compilation containing 4483Mb of data, and started the write process. We used the Disc-At-Once write method.

DVD+R

DVD-R

The DVD+R disc was finished in 7 minutes and 3 seconds, while the DVD-R disc was finished in 6 minutes and 50 seconds. This looks higher than expected, one reason is that the drive uses Z-CLV writing technology the other reason is that our test sample would never upshift to 16x (except for one case which is shown above when showing the writing strategy).

*Actual writing speed is 12x.

The Pioneer DVR-A08XLA ends up slower than all the other drives, including the 12x DVD-Writer Plextor PX-712A. Disappointing, but let's see if the writing quality makes up for it.

Write quality:

You should first notice that this is not a scientific and professional way to test the discs. But according to our testing done in recent months, 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 this test we use a Lite-On SOHW-832S 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/PO 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, as different drives report different amount of errors, some players are more picky about media than others, and so on. But as a comparison we present you with a scan from two pressed DVD discs:

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 thePO (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 scanned at 4X CLV due to lower speeds taking to much time.

To see if there is a connection between the reported amount of errors and readability of the discs we also include the reading curve from a NEC ND-3500AG DVD-Writer. The reason why we have changed reader is that some companies disliked that we used a modified firmware to obtain 16x reading speed. So to please them we are now using a drive that reads DVDR media at 16x as default. 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.
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.

And as always; lower is better

And look at the reading curve; does it look clean with no dips it should be good, a small slowdown near the end is accepted.

DVD+R media compatibility and write quality:

Give us a break! This media has been available for about a year and is still not supported at 8x? Very disappointing! The writing quality is ok though with only a slight reading problem near the end.

A very good result, no problems here!

The drive performed very well with the prodisc media and we have no problems recommending this media.