Performance during CD-RW Media Processing

From write-once media we can go over to rewritable discs:

The drives take almost the same time to perform this task, which is quite natural considering their identical burn speeds. We have one difference, though. The older model refused to work with 32x rewritable discs, while the Plextor PX-716A successfully burned such a disc at 24x speed. Now, let’s examine the quality of the resulting discs:

 

Plextor PX-716A burning/reading a 24x CD-RW disc at 24x speed

The new model uses the P-CAV algorithm for burning 24x CD-RWs. It also takes very little time to reach the maximum speed, so it has one of the fastest overall results in its class. The minor throbbing of speed at the beginning of the disc didn’t affect the overall burn time. Judging by the problem-less reading of the written disc, we can expect a high burn quality, again.

 

Quality of 24x CD-RW burning by Plextor PX-716A at 24x speed

The quality is excellent on the whole. The average BLER across the entire surface of the disc is below 20, save for the outermost tracks. But the drive made a slip at the end of the disc ?there is a surge of first encoder errors there, and quite a number of C2 errors which have been missing before. That’s no very crucial, though, as to a signal of a bad burn quality. It is not perfect, yes, but it’s not bad, either. On the other hand, the disc couldn’t pass the Beta/Jitter test, which aborted at the same very spot where there was the surge of errors. Until that moment, the jitter rate and the asymmetry are both within the norm. I tried to read this CD-RW in several other drives and each of them read it correctly, without any errors. So again, the results of this test seem worse than they really are ?the quality is acceptable and even excellent if we disregard the outermost tracks. The problem may come from some imperfections in the burn strategy or may be due to a single failure in the operation of the device’s logics. This defect will hopefully be corrected in the next firmware update, and the new Plextor will have a near-etalon burn quality with rewritable CDs, too.

 

Plextor PX-716A burning/reading a 32x CD-RW disc at 24x speed

The burning was done without any problems like speed slumps or anything. The drive reached its maximum speed the same moment as it did with the 24x CD-RW disc ?this explains the identical burn times. The read graph for the resulting disc has a curious shape, though. It’s unusual ?the jagged read curve and the perpetually changing speed indicate that there’s something wrong with the quality of the written disc. Let’s see what it is, exactly.

 

Quality of 32x CD-RW burning by Plextor PX-716A at 24x speed

Here’s the answer ?we’ve got an abnormally high level of first encoder errors. Moreover, there are C2 errors on the disc, including 22 uncorrectable E32 errors. It’s no wonder then that the disc just couldn’t pass the Beta/Jitter test.

Although the drive did burn a 32x CD-RW, the quality of the resulting disc is very low. The disc is readable, but I wouldn’t vouch for its readability in other drives. But on the other hand, the Plextor PX-716A doesn’t support 32x CD-RWs officially.

So, here’s my summary of the CD-related part of this review: the new Plextor produces CD-Rs of an excellent quality at both maximum and minimal speeds, but has some problems with CD-RW media. But after the next firmware update (I’m absolutely sure it’s going to be released soon) the Plextor PX-716A will surely become one of the best optical drives for processing CD-R/RW media. You may remember the times when Plextor’s drives were awful with these types of media, but it is different now ?the manufacturer has realized at last that users are still interested in the CD part of an optical combo-drive.

Yet, the new Plextor still refuses to read bad, damaged CDs. There should have been a section in this review about the drive’s reading a damaged CD-ROM, but the PX-716A just stopped after the first bad (unread) sector, and I couldn’t urge it on to continue ?I had to extract the disc to unfreeze the system. I don’t know why, but the manufacturer must have some reasons for ignoring your having bad compact discs.