While building a SharePoint farm for a project, i did load testing with VSTS.
Since my SharePoint farm was in a different domain than that of my Load test controllers, I had to monitor few performance counters to take a well informed decision while tuning the farm capacity.

Below powershell was developed by me to generate a html report for all the different servers at specified intervals.
The output html file will be generated in D Drive. 

#Array which contains the different Server names
$ServerList  = @('server01', 'server02', 'server03','Server04','Server05')

#Array which represents the role of the server
$ServerRole=@('WFE1', 'WFE2', 'Central Admin', 'WorkFlow1','WorkFlow2')

#Number of times this powershell should be executed
$runcount = 15;

$Outputreport = "<HTML><TITLE> Server Health Report </TITLE>
                     <BODY background-color:peachpuff>
                     <font color =""#99000"" face=""Microsoft Tai le"">
                     <H2> Server Health Report </H2></font>
                     <Table border=1 cellpadding=0 cellspacing=0>
                     <TR bgcolor=gray align=center>
                       <TD><B>Server Name</B></TD><TD><B>Server Role</B></TD>
                       <TD><B>Avrg.CPU Utilization</B></TD>
                       <TD><B>Memory Utilization</B></TD>
                       <TD><B>C Drive Utilizatoin</B></TD>

for($i=1; $i -le $runcount;$i++)

    $ArrayCount = 0
    ForEach($computername in $ServerList) 

        $role = $ServerRole[$ArrayCount]
        $ArrayCount = $ArrayCount  + 1
        Write-Host $i $computername $role 

        $AVGProc = Get-WmiObject -computername $computername win32_processor | 
        Measure-Object -property LoadPercentage -Average | Select Average
        $OS = gwmi -Class win32_operatingsystem -computername $computername |
        Select-Object @{Name = "MemoryUsage"; Expression = {“{0:N2}” -f ((($_.TotalVisibleMemorySize - $_.FreePhysicalMemory)*100)/ $_.TotalVisibleMemorySize) }}
        $vol = Get-WmiObject -Class win32_Volume -ComputerName $computername -Filter "DriveLetter = 'C:'" |
        Select-object @{Name = "C PercentFree"; Expression = {“{0:N2}” -f  (($_.FreeSpace / $_.Capacity)*100) } }
        $result += [PSCustomObject] @{ 
                ServerName = "$computername"
                CPULoad = "$($AVGProc.Average)%"
                MemLoad = "$($OS.MemoryUsage)%"
                CDrive = "$($vol.'C PercentFree')%"

        Foreach($Entry in $result) 
            if(($Entry.CpuLoad) -or ($Entry.memload) -ge "80") 
            $Outputreport += "<TR bgcolor=red>" 
            $Outputreport += "<TR>" 
            $Outputreport += "<TD>$($Entry.Servername)</TD> <TD>$role</TD>  <TD align=center>$($Entry.CPULoad)</TD><TD align=center>$($Entry.MemLoad)</TD><TD align=center>$($Entry.Cdrive)</TD><TD>$i</TD></TR>" 

        $result = $null

$Outputreport += "</Table></BODY></HTML>" 
$time = $(get-date -f MM-dd-yyyy_HH_mm_ss) 
$file = 'D:\' + $time + '.htm'

$Outputreport | out-file $file

Invoke-Expression $file