The metric label section within the configuration of many Performance tiles (not Heatmap and Scalar tiles) (see How to use the Performance tile) in v4.8 and above allows you to specify metric units, which are then shown on the y-axis and hover value.
While SCOM does not return the units, such as % or MB, the metric name often includes the units.
You should select the label that matches how the the data is being returned. For example, if the data being returned is in MB then select megabytes.
The other option allows you to specify a custom metric label, such as "pages/sec" or "count".
When bytes, megabytes or seconds are selected SquaredUp will 'scale up' the label to MB, GB, minutes or hours as appropriate. When using the preconfigured options SquaredUp will also convert very small or large values which would normally be displayed as m, µ, k or M into the selected (or upscaled) metric. See Understanding the figures on Performance graphs.
The Bar Top n graph below shows a figure of 1.71k:
This is actually 1709, as you can see when hovering over the figure. The metric name shows that this figure is returned in MB.
When the metric label is changed to megabytes SquaredUp shows 1.67GB:
This is 1709 divided by 1024 and rounded to two decimal places to convert MB into GB.
Clicking on the Bar Top n graph takes you to the drilldown page, and when the time period is changes to show the same aggregation then the 1.71k avg figure is shown. This is because Performance drilldowns cannot be configured like tiles, so will continue to use m, µ, k or M.
Why are all the values shown as zero ?
When no metric label is set very small values will use m (milli) or µ (micro):
With the metric label set to percent, the very small values are rounded up to one decimal place, and therefore they can all show as 0.0% :
When values are so small it's best to leave the metric label set to other, and interpret the very small figures as described in Understanding the figures on Performance graphs.