detail information

 

The specifications of this drive tell us that it should write DVD-R discs at 4x and DVD+R discs at 8X speed. In this part we will measure the write time for various types of DVD-/+R discs. We do also focus on write quality and media compatibility.

DVD-Writing performance:

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In this test we will measure the time for writing to DVD-R and DVD+R discs. We used Nero burning Rom to set up a new UDF/ISO compilation containing 4482Mb of data, and started the write process. We used the Disc-At-Once write method.

DVD+R

DVD-R

Look below for the results.

Write DVD data discs	DVD+R	DVD-R
Plextor PX-708A	8m:01s	14m:57s (4x speed)
NEC ND-2500A	9m:34s	9m:30s
Lite-On LDW-811S	8m:43s	15m:07s  (4x speed)
Pioneer DVR-107D	8m:45s	8m:27s
NU DDW-082	8m:02s	14m:26s  (4x speed)
Lite-On SOHW-812S	8m:40s	9m:29s
BenQ DW822A	8m:26s	16m:13s (4x speed)

AS we could see the BenQ DW822A is pretty fast at writing DVD+R discs at 8x, but very slow at writing DVD-R discs at 4x. The reason why it's so slow at 4x DVD-R writing is partially that it uses long time to write the lead-in/lead out and partially that it uses walking OPC to ensure the highest possible writing quality.  Let us see if the walking OPC feature really works, and take a look at the writing quality of the BenQ DW822A.

Write quality:

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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, PO (Parity Outer) set to summarize 1 ECC block, reading speed: 4X CLV (Constant Linear Velocity). Setting the PI sum to 8 and the PO 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 is 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 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 PO errors that K-Probe reports? Actually the PO errors that K-Probe reports is the Parity Inner uncorrectable errors, meaning errors left after PI correction. Only the ECMA 337 standard describes the Parity Inner uncorrectable errors. So how is a Parity Inner uncorrectable error 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 PI uncorrectable errors since every ECC block is 208 rows long. But the ECMA 337 standard goes further and specifies the max amount of accepted PI 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 PO sum is set to 1 the maximum error value should not exceed 4. The theoretical maximum value for PO errors is 208 errors.

But what makes a disc unreadable? A PO uncorrectable error will make the disc unreadable, but K-Probe does not display the PO uncorrectable errors.

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 JLMS XJ-HD165H DVD-ROM that seems to be pretty easy affected by the quality of a written disc.

Easier explanation on how to read the test results.

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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.
PO(Parity Outer): No larger areas on the disc should exceed 4 PO-1 (actually PI uncorrectable) 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, a slight slowdown at the end is probably nothing to worry about, but huge bumps and slowdowns are not good.

DVD+R media compatibility and write quality:

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First you should notice that since we have written the discs with Nero and the booktype is set to DVD-ROM our JLMS XJ-HD165H DVD-ROM will try to read the disc at full 16x speed. This of course requires the disc to be almost perfect, which most recordable isn't. So there will be slowdowns at the end for most discs.

 

While the K-Probe result is not the best we have seen it's still very good and we got a very nice reading curve all the way up to 16x. Highly recommended.

 

Brand:	SKS Claudia
Manufacturer:	Ritek
Code:	RITEK R03 (Revision 001)
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:21s
PI-8 errors Average/Sec:	25.86
PI-8 uncorrectable errors( PO) Avg/Sec:	0.00

Pretty good result, but the reading curve is a bit bumpy at the end. But still highly recommended.

Brand:	Verbatim DataLifePlus
Manufacturer:	Mitsubishi (Real Mitsubishi discs from )
Code:	MCC 003
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:36s
PI-8 errors Average/Sec:	1.94
PI-8 uncorrectable errors( PO) Avg/Sec:	0.00

Well, it's Taiyo Yuden. And the result is right where it should be. Excellent and highly recommended.

 

Brand:	Plextor
Manufacturer:	Taiyo Yuden
Code:	YUDEN000T01 (Revision 001)
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	8x
Write Time:	8m:23s
PI-8 errors Average/Sec:	1.97
PI-8 uncorrectable errors( PO) Avg/Sec:	0.00

The result seems to be about the same as for the 8x Mitsubishi DVD+R media. Some bumps at the end, but still recommended media.

 

Brand:	Verbatim Data Life Plus
Manufacturer:	Mitsubishi (Real Mitsubishi disc from )
Code:	MCC 002
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	8x
Write Time:	8m:26s
PI-8 errors Average/Sec:	3.15
PI-8 uncorrectable errors( PO) Avg/Sec:	0.01

Simply amazing! The results show that the BenQ DW822A is fully optimized for the Ricoh media. Highly recommended media for this drive.

 

Brand:	Arita
Manufacturer:	Ricoh (by Ritek)
Code:	RICOHJPNR01
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	8x
Write Time:	8m:29s
PI-8 errors Average/Sec:	0.43
PI-8 uncorrectable errors( PO) Avg/Sec:	0.01

While the result is still good it's not as good as the other discs we have tested so far. Should not cause any playback problems in most drives.

 

Brand:	Memorex
Manufacturer:	CMC Magnetics
Code:	CMC.MAG.F01 (revision 000)
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	8x
Write Time:	8m:37s
PI-8 errors Average/Sec:	11.11
PI-8 uncorrectable errors( PO) Avg/Sec:	0.00

The BenQ DW822A do of course work excellent with BenQ brand media! Highly recommended.

 

Brand:	BenQ
Manufacturer:	Daxon
Code:	DAXON.AZ1
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	8x
Write Time:	8m:21s
PI-8 errors Average/Sec:	3.45
PI-8 uncorrectable errors( PO) Avg/Sec:	0.01

There is an error spike at the beginning of the disc as usual with this media. But overall there is no serious problems and you should not have any problems using this media.

 

Brand:	BulkpaQ Generation 4
Manufacturer:	Unknown
Code:	MEDIA ID001
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	4x
Write Time:	14m:51s
PI-8 errors Average/Sec:	6.94
PI-8 uncorrectable errors( PO) Avg/Sec:	0.02

The writing quality with BeAll DVD+R media is very good and we could highly recommend these discs.

To see if rather unknown media types are supported at certified speed we include the following table:

Brand:	BeALL
Manufacturer:	BeALL
Code:	BeAll000P40
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	4x
Write Speed:	4x
Write Time:	14m:49s
PI-8 errors Average/Sec:	1.26
PI-8 uncorrectable errors( PO) Avg/Sec:	0.01

DVD+R Brand	Manufacturer	Media code	Certified Write Speed	Supported Write Speed
Sky	Unknown	AML 002	8x	8x
Lite-On	Ricoh	RICOHJPNR02	8x	8x
Fortis	Daxon	DAXON.AZ2	8x	8x
Norwaydisc.no	Nanya	NANYA.RJB	8x	8x
Fortis	Nanya	NANYA.RJB	4x	4x
Unbranded	Unknown	PITSEXP 002	4x	4x
Unbranded	Unknown	AML 001	4x	4x
Unbranded	Unknown	IS01001	4x	4x
Unbranded	Unknown	VDSPMSAB001	4x	4x
Unbranded	Unknown	001	4x	4x
MMORE	Opto Disc	OPTODISCOR4	4x	4x

Very good DVD+R media compatibility as all discs were supported at certified speed.

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