detail information

Writing Quality with CD-R/RW discs

Now we are going to test CD-R discs from different CD-R manufacturers.  To measure the write speed we will use the “Create Data CD” function from within Nero DiscSpeed.  We wrote these discs at the maximum speed that the drive supports.  For the quality test, we also used Nero DiscSpeed.  DiscSpeed runs under Windows and supports several drives.  Also note that different drives and different reading speeds may affect the results obtained when scanning the discs.  We used a BenQ DVD DW1650 with firmware BCDC and scanned these discs at 48X speed.

Disc Quality Scanning - C1/C2 (and CU); here is an explanation in more detail:

CDs use an error detection and correction system (CIRC) which is for the most part not seen by the user when reading the disc.  We can get a working idea of the quality of the media in question by performing Disc Quality Scanning that will show us the amount of errors the drive is detecting and correcting while reading the media.

There is more than one way to handle C1 and C2 error detection/correction, but a simple and common way is to detect and correct up to two errors per frame in each stage and detect three or more errors:

• E11: 1 error detected and corrected by C1 layer
• E21: 2 errors detected and corrected by C1 layer
• E31: 3 or more errors detected but not corrected by C1 layer

The sum of these (per second) is called the BLock Error Rate: BLER=E11+E21+E31

• E12: 1 error detected and corrected by C2 layer
• E22: 2 errors detected and corrected by C2 layer
• E32: 3 or more errors detected but not corrected by C2 layer

Any E31 is uncorrectable by the C1 layer and will result in the bytes in that frame being redistributed into multiple frames which are passed to the C2 layer.

Any E32 is uncorrectable by the C2 layer and will result in interpolation being used for Audio CDs or will result in third layer error correction being use for Data CDs.

Different drives have different ways of reporting these errors in a Disc Quality scan.  For example the following drives will report C1 and C2 errors this way:

BenQ DW1650 Disc Quality:

• C1=BLER=E11+E21+E31
• C2=E32

BenQ DW1650 Advanced Disc Quality:

• All errors are reported separately as well as BLER=E11+E21+E31

Lite-On SOHR-5239V:

• C1=BLER=E11+E21+E31
• C2=E32

Here is a little easier way to look at Disc Quality Scanning:

A written CD-R disc will always have some C1 errors; C1 errors are easily corrected by the drive's error correction capabilities.  The next level of errors is C2, while C2 errors could also be corrected by most drive's error correction capabilities; multiple C2 errors in the same frame are not wanted on a good quality disc.  A good disc should not contain any C2 errors of the E22 or E32 kind, and preferably have an average C1 error amount of below 2.0 for the best quality discs, or at least below 10.0 averages for good quality discs.  After C2 errors, there are only un-correctable errors that will make a disc unusable.

So, in short, our analysis will be based on these guidelines to determine the quality of the burned discs which will be Quality Scanned on our BenQ DW1650:

CD-R/RW quality scans guideline

Below you will see our obtained results:

Writing Data CD-R discs

For our data writing tests, we simply set up a new compilation of 703Mb using Nero Burning ROM software. Writing method used is DAO (Disc At Once), and the disc is set up as a non-multisession disc with “finalize disc” enabled. The screenshot below shows how long it takes to write a disc at the highest speed. (48x):

The ASUS DRW-2014L1T completed this burn in 3 minutes and 20 seconds.

Now let’s take a closer look at writing quality using CD-R media with the ASUS DRW-2014L1T.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

An excellent result to start our CD-R quality tests, no C2 errors reported from the Lite-On drive and no E22 or E32 errors reported from the BenQ scan.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

The ASUS DRW-2014L1T burned this media with very good results.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

The ASUS DRW-2014L1T did not fare as well with this media with the existence of E22 errors.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

This ASUS DRW-2014L1T handled this media with very good results also.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

Overall these results reflect some E22 errors on our ADQT with our BenQ drive suggesting this is not as good a quality burn as we would like to see; even though the LiteOn with Kprobe shows the burn to be of good quality.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

Here we see very excellent results with this media.

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

The ASUS DRW-2014L1T writes to this media with excellent results.

Now we will see how the ASUS DRW-2014L1T performs with our CD-RW media…..

Writing Quality with Re-Writable discs

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

The ASUS DRW-2014L1T did not do well with this media which can be problematic with some burners.

We will also test the ASUS DRW-2014L1T with the Memorex 12X CD-RW disc:

Advanced Disc Quality Scan with Stats at 16X CLV

Disc Quality Scan at 48X

The ASUS DRW-2014L1T was able to write to this media with excellent results.

Summary

Overall the disc quality scans on our Lite-On 5239V with KProbe show very good results, however, from our Advanced Disc Quality test with our BenQ drive we can see some E22 errors on Daxon and Ritek CD-Rs and Verbatim CD-RW which we would like to see improved.

Since this is a DVD-Writer, let’s head on to next page and read about DVD-Writing performance and DVD media compatibility…

On the next page let’s take a look at the DVD+R/RW Writing Performance…

Reading Performances 

DVD+R/RW writing performance