Writing Quality with CD-R/RW discs

The specifications of the LG BH08LS20 state that the drive is able to write CD-R discs at 48X and CD-RW discs at 24X. Let’s find out how the drive really performs in speed and quality.

For our data writing tests, we simply burned a full disc using CD-Speed (create data disc) function and burned the discs at the maximum speed allowed.

Let us find out how the drive really performs in speed and quality.

Write quality:

We will test CD-R discs from many different CD-R manufacturers. To really measure the write speed, we used the “create data CD” function in Nero CD-DVD Speed. The discs were written at the maximum speed that the drive supports. For the quality test, we used Nero CD-DVD Speed’s Advanced Disc Quality Scan and combined this with a Transfer Rate Test to test if the resulting disc was readable. Also note that different drives and different reading speeds may affect the results obtained when scanning the discs. We used a BenQ DVD DW1655 with firmware BCIB under Advance Quality Scan and scanned these discs at 16X CLV speed; as well as a Disc Quality Scan at 48X speed.

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

• E32: 3 or more errors detected but not corrected by C2 layer

Any E31 is un-correctable 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 un-correctable 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.  Lite-On CD-RW drives will report C1 and C2 errors this way:

• C1=BLER=E11+E21+E31
• C2=E32

BenQ DW1655 Disc Quality

• C1=BLER=E11+E21+E31
• C2=E32

BenQ DW1655 Advanced Disc Quality

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

Here is an 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; they are not wanted on a good quality disc. A good disc should not contain any C2 errors, and preferably have an average C1 error amount of below 2.0 for the best 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 DW1655:

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 LG BH08LS20 completed this burn in 2 minutes and 44 seconds.

Now let’s take a closer look at writing quality using CD-R media with the LG BH08LS20.

Quality Scan with BenQ DW-1655

TRT with the BenQ DW-1655

The LG BH08LS20 burned this test media with C1 average errors of 3.41, a good quality burn.

Quality Scan with BenQ DW-1655

TRT with the BenQ DW-1655

The HP media manufactured by CMC Magnetics has burned with good quality.

Quality Scan with BenQ DW-1655

TRT with the BenQ DW-1655

The LG BH08LS20 burned with a higher C1 error average than we like with this Daxon media from Imation.

Quality Scan with BenQ DW-1655

TRT with the BenQ DW-1655

The LG BH08LS20 produces an “Excellent” quality burn, this time with our Taiyo Yuden media; check out the C1 and C2 errors. 

Quality Scan with BenQ DW-1655

TRT with the BenQ DW-1655

Our Verbatim CDR Test disc manufactured by CMC Magnetics burned with excellent results.

Writing Quality with Re-Writable discs:

Quality Scan with BenQ DW-1655

TRT with BenQ DW-1655

We would like to see better results with our 32X Verbatim test media.

Summary:

CD-R writing quality was overall Excellent with the LG BH08LS20.  We would like to see better performance when burning 32X high speed CD-RW media.

Now let’s head on to the next page where we will test DVD recordable performance….