DVD+R written at 12x speed

The use of the Z-CLV mode with three zones ensured a certain speed gain as we switch from 8x to 12x. The difference is slightly over one minute. The burn process went smoothly, like at 8x speed, but the burn quality has degenerated considerably compared to lower speeds, although is still in the acceptable “readable” limits. The PO error level hasn’t changed practically, but the PI error level is high as soon as the drive starts working at 12x. The graph of reading the written DVD provokes even more questions. The zones written at 4x and 12x (!) are read normally, while the 8x zone poised some reading problems. First, there’s a significant speed drop and, second, there’s “beating” of speed in this zone at reading. Overall, considering the Z-CLV burn mode and a consequential minor time gain from 12x speed (while the quality is much lower), I think it is better to burn discs at 8x and lower speeds with the Lite-On SOHW-1213S drive. The results for 4x and 8x speeds are just excellent.

  

DVD-R written at 4x speed

Again, the burn process went smoothly. The quality of the written blank is somewhat worse than with the DVD+R disc written at the same speed, but is anyway high enough. The PI error level is in the norm, but higher than with the 4x DVD+R. The PO errors are few, and PO error blocks don’t occur frequently. The disc was read without any problems, too, but at a smaller speed than the DVD+R medium.

  

DVD-R written at 8x speed

This is different from what we saw with the 8x DVD+R disc. The Z-CLV burn algorithm is used in both cases, but it consists of two stages for DVD+R and writing starts from 6x, while for DVD-R we have three stages and writing starts from 4x. This explains the difference (53 seconds) in time it took to burn DVD-R and DVD+R discs at 8x speed. The difference is no big deal, but the use of one more stage in Z-CLV also affects the quality of the resulting disc. Some drives falter at those spots where the zone changes and greatly reduce their reading speed.

The quality of the disc can be called good, but not excellent. The PI error level is low (but higher than with analogous DVD+R discs), and the level of PO errors grows up at the end of the disc, at 8x speed. Of course, 7-8 is far from the limit (32), but worse than 2 as we had above. The graph of reading the resulting DVD is stable.

The overall quality of burning DVD-R discs is lower than that of the DVD+R discs, and the quality degenerates more as you switch to 8x speed. Moreover, the additional stage that appears when you burn 8x DVD-Rs at 8x speed worries me, too.