Inconsistant data in performance reports

Hi,

My environment is vCenter Server 4, vSphere ESX 4, and PowerCLI 5.1

Right now I am gathering the resource pool cpu performance data using powercli for a monthly performance report..

I use the get-stat command to obtain the data and then export that into a csv file.

When I look at the data I retrieved and compare it with the performance report which you can generate from the vCenter GUI, the data is inconsistent. I get about twice as much MHz from the get-stat command then that of the vCenter report. Why does this happen and is there a way to correct this problem? Maybe my commands aren’t right….

Here are the commands I use to get resource pool cpu performance.

$midnight = (Get-Date -Hour 0 -Minute 0 -Second 0)

$rp1 = Get-ResourcePool -Location cluster1

$metrics = "cpu.usagemhz.average"

Get-Stat -Entity ($rp1) -Stat $metrics -Start $midnight.adddays(-1).addminutes(-1) -Finish $midnight.addminutes(-1) | Select-Object timestamp,value,unit,metricid,entity | Export-Csv "C:/csvfiles/file1.csv"

any help would be appreciated!