Question: Why doesn't the CPU data shown in VMWare match the data gathered by vFoglight?
Answer: VMWare rolls up the collected data differently than vFoglight rolls up data, which can cause the peaks in the data to be different values. If you compare the rolled up data in VMWare to the real time data in VMWare the difference in the peaks is noticeable. It would be best to look at the newest real-time data in VMWare versus the real-time data in vFoglight for the same time period when making a comparison. When comparing the real-time data the values should be quite similar. Foglight data is typically rolled up after 15 minutes so you will need to look at the last 15 minutes of data when doing the comparison.
In the vSphere client you can select the Real time CPU data with the following steps in the vSphere client:
1). Highlight a VM host.
2). Select "Performance | Advanced", select CPU in the "Switch to" drop down.
3). If real-time data is not being shown you can switch to real-time data by selecting "Chart Options", expanding the CPU section, and then clicking on real time.