The specifications of the Optiarc AD-7240S state that the drive is able to write CD-R discs at 48x and CD-RW at 32x. Let us find out how the drive really performs in speed and quality.

Writing Data CD-R discs:

For the 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.

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-Speed. The discs were written at the maximum speed that the drive supports. For the quality test, we used Nero CD-Speed’s 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. For the Disc Quality Scan a NEC ND-3540A drive with firmware 1.04 was used to scan the discs at 48x speed while an Optiarc AD-7201S was used for the Transfer Rate Test. 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 used for Data CDs. Different drives have different ways of reporting these errors in a Disc Quality scan. 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. In short, our analysis will be based on this guideline to determine the quality of the burned disc:

CD-R/RW quality scans guideline

Below are the obtained results:

The CD-R tests started with an excellent result. However the end of the disc showed an increased C1 error rate, but it is unclear whether it was caused by the drive or the media and the written disc itself had no C2 errors and was perfectly readable.

C1 error rates are low on this disc again and the read back test was perfect too.

The result with these Verbatim CD-R discs is excellent again. Highly recommended discs for this drive.

Again the drive performs well on these HP branded discs.

The result is good again but error rates are a little higher than what we got from different discs.

Writing Quality with Re-Writable discs:

C1 errors are high at the start of the disc, but overall the result is excellent.

Summary:

CD-R writing quality is generally good to excellent as C1 error rates are mostly low and we did not have a single C2 error. CD-RW writing quality on our tested media was great too so this drive can be highly recommended for burning CD-R and CD-RW media Now let’s head on to the next page where we will test DVD recordable performance….

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