X-bit labs

LiteOn SOHW-1213S Dual DVD±RW Recorder Review (page 5)

Category: Storage

by Vasily Melnik

[ 10/08/2004 | 12:04 PM ]

I’m going to start with the maximum burn speed. This time it is 48x.

Burn quality of the Lite-On SOHW-1213S drive at 48x speed:
scaled-down and full-size (0.87MB) image

When the written disc is being read at 4x speed (the speed the CD CATS SA3 system works at) the BLER parameter differs somewhat from what we saw above using the Plextor PX-712A drive at 24x speed. There are significant C1 error peaks at the beginning and end of the disc, which result from “fuzziness” of pits and lands and their partial overlapping. The higher the speed, the more difficult it is for the drive to identify them. The total of errors of both first and second encoders is very small, though. There is a single surge of E32 errors, but it must be due to a defect of the medium itself because the BERL parameter is above the norm in this spot, too.

Now let’s discuss the symmetry parameter, which is the analog of the Beta parameter as measured with the help of the PX-712A. The results we got above are fully confirmed: starting from the 60‑th minute, symmetry is out of the acceptable range. This corresponds to the moment the Beta/Jitter graph goes above the 0.00 point. Jitter is normal; its fluctuations are negligible and far from the maximum allowable values. There are only minor jitter peaks for lands. The Land Histogram shows overlaps for lengths of up to 8T inclusive. The overlap area is rather large for small-size sequences (3T-5T), which indicates that the drive has problems creating small-length pits.

The Reflection parameter is below the norm – yet another DVD-burner shows the common problem of this category of devices.

OK, let’s drop the burn speed to 24x and view the results.

Burn quality of the Lite-On SOHW-1213S drive at 24x speed
scaled-down and full-size (0.54MB) image

It’s overall similar to what I have had when reading the disc in the Plextor PX-712A. The BLER is somewhat smaller; there are no E22 errors; the BERL parameter is normal across the entire surface of the disc. Symmetry (i.e. Beta) is within the acceptable range. Jitter is acceptable, too, both for pits and lands. The histograms confirm that as there are no overlapping areas in them. So, as I have said above, the burn quality improves as we drop the burn speed from 48x to 24x. The only problem with 24x is the reflection coefficient, but we have to put up with it when it comes to DVD-burners. I haven’t yet met a device that would have this parameter within the norm.

Now let’s switch to 16x speed.

Burn quality of the Lite-On SOHW-1213S drive at 16x speed
scaled-down and full-size (0.67MB) image

The BLER has become smaller yet, although the reduction of C1 errors is small compared to 24x. There are still E22 errors on the written disc. The BERL is within the norm across the entire CD-R. Surprisingly, the land jitter has become bigger at the reduced burn speed! It is slightly above the norm almost for any pit length. Accordingly, there are minor overlaps in the Land Histogram for small-length pits. Yet another curious thing – symmetry (beta) becomes the maximum possible starting from the 60-th minute, like with 48x speed burning. From there on, it is slightly above the norm.

Summarizing the results of the Lite-On SOHW1213S with CD media, I would like to stress the following facts. Successfully handling CD discs overall, the Lite-On had the best results when writing at 24x speed. At the maximum burn speed, there are problems with land lengths and a deviation of symmetry out of the acceptable range. 16x burn speed also produced some strange results: the same symmetry-related problems, although less evident than at 48x speed, and the same problems with land lengths. So, the total result is somewhere between “satisfying” at the maximum to “good” at 24x speed. Considering the strengthening trend to eliminate CD-R support in DVD-burners (this can be assumed from the total indifference of the optics manufacturers to the problems of their devices with CD-R discs), the results of the SOHW-1213S can be considered acceptable. At least, against its competitors.