A second problem I have with PlexTools 2.17 is that the DVD â€œjitterâ€ measurements are almost completely useless because:
(1) There are no indications what the scale is or (more important) where zero is.
(2) The jitter graph readjusts itself vertically, jogging up if the graph threatens to go off the bottom of the scale. So no two graphs can be compared!
True, the shape of the graph can be seen, i.e. how whatever itâ€™s measuring varies over the recorded area of the disk. But what clue do we have as to the absolute values being displayed?
Itâ€™s as if Plextor wanted to include some kind of Jitter Graph but didnâ€™t want to reveal too much!
Look at the attached image for an good example of this vertical shifting of the jitter graph. My experience so far is that any jitter graph begins in the lowest major division of the vertical scale. If the graph then heads upward, no problem, the graphs remains stationary (Fig.1).
But look what happens if instead the graph heads south! Fig.2 shows 4 snapshots taken while a disk was being read. As the graph tends lower, the graph shifts upward three times! So … are these high or low values? Does the graph always start off in that lower-left corner and gets tweaked if it goes lower? What is the display strategy? Where is zero? (Ignore the downward spikes; thay are harmless artifacts of my setup.)
I feel this is a nearly-useless display. It could have been done properly, but wasnâ€™t. Is anyone at Plextor thinking this through?