A common question our customers ask is something similar to “Why does the text on the bottom of the graph have a ‘Max Blocks written’ value of 81.023K, yet the Y-axis of the graph only goes to 40K”?
The shortest (and easiest) explanation is that the graphs have a limited amount of real estate to use on the display (depending on your screen width). The longer explanation is that in a 30-day graph like the one above, we only have 660 pixels or so to display 8,640 horizontal data points. So, even though the actual values are in the system; in order to draw the graph in the space available, we have to display an average of the data points. Thus, the line you see in the graph is the average, and not the max, of the data.
Averaging data in this manner will inevitably blunt some of the peaks. You can, however, force the peaks to be visible on the graph in one of two ways: either click-and-drag to zoom into the histogram (thus looking at a smaller time frame), or select the option in the query box labeled “Peaks” and then click GO to redraw the graph.
So, the same graph with “Peaks” enabled looks like this:
You can see that the peak data can cause the graphs to become a little cluttered, which is why this option is disabled by default.