Both models use the P-CAV algorithm for writing DVD+R discs at this speed. They also take the same time to achieve the maximum burn speed. The Plextor PX-712A couldn’t complete the burning at 12x, but slowed down to 10x and then to 8x. The PX-716A, on the contrary, successfully burned the disc through at 12x speed. But surprisingly, the difference in time between the two drives is only 6 seconds. I used the same blanks with both drives and didn’t disable the PoweRec mechanism. Thus, we have not only improvements in the burn strategy, but also in the optical system in the new model.

We can also see differences in the drives’ reading the resulting disc. The previous model dropped its read speed on the outermost tracks, just as it did when burning them. The Plextor PX-716A read the disc at the maximum speed, which is another confirmation of the point that the optical system has been improved. Now let’s check out the quality of the disc, too.

The difference is small, but noticeable: the number of PI errors has diminished from 18,184 to 13,086, and the number of PI failures from 181 to 55. This gap is wide enough for me to talk about a much better burn quality achievable with the new model. Note also that the level of PI errors and failures is higher at the beginning of the disc written by the PX-712A than at its end, but we don’t see the same with the disc burned in the new model. It makes me suppose the OPC mechanism has also been improved in the Plextor PX-716A.

Beta/Jitter and TA Test (Inner, Middle, Outer)
for the disc burned by Plextor PX-716A
 
 

The asymmetry of the disc is normal, but the jitter rate is not constant but fluctuating along the surface of the disc. It’s only after the drive has reached the maximum burn speed that the jitter graph becomes almost a perfect straight line. It seems like the drive had some problems with setting up the laser power accurately when working according to the CAV algorithm.

The results of TA Test, however, show that the drive maintains the lengths of pits and lands quite well. There are minor overlaps with small lengths, but the result is good overall. So, the written disc is of high quality, without doubt. Now let’s switch to the maximum, 16x speed.