24x Speed

 
 
Burning/reading the CD-R disc at 24x speed:
LG GSA-4163 (left) and LG GSA-4160B (right)

The Z-CLV algorithm is in use, again. And the program identifies this algorithm correctly for the new device (the burn algorithm is wrongly identified as CLV for the GSA-4160). This is all rather strange because many manufacturers use P-CAV for this burn speed, but LG stubbornly sticks to the outdated Z-CLV. On the other hand, this burn algorithm is simple in implementation – maybe this is going to positively affect the quality of the written discs. The burned disc was really read without errors, but the read graphs resemble those for 40x speed: the maximum read speed is achieved and there are no obvious slowdowns, but the spindle speed and the data-transfer rate are varying a little.

 
 
Quality of the CD-R disc burning at 24x speed:
by LG GSA-4163 (left) and by LG GSA-4160B (right)

The new model again performs much better than the GSA-4160. The number of C1 errors has diminished from 18,641 to 5187, i.e. almost in three times. C2 errors appeared on the outermost tracks of the disc written by the new model, but it is a defect of the medium rather than of the tested optical drive – the errors are all grouped at a single spot of the disc. Like at 40x speed, the Beta/Jitter graphs of the GSA-4160B display a step-like increase of the asymmetry at the moment of transitioning from 16x to 24x burn speed. But the beta value is overall quite acceptable, and the graph itself is almost a perfectly flat line (if you don’t count in the moment of the transition). The jitter rate is more uniform than at 40x, but the graph is still somewhat wavy. If you compare these results to the parameters of the disc written by the new model, the difference strikes you immediately: the asymmetry is almost at zero again, while the jitter rate is lower than with the previous model. Thus, the GSA-4163 has again bettered its predecessor, and the difference is quite considerable.