PHP and Windows WMI, CPU Temperature and false readings? - php

Question

I wrote this PHP function:
<?php
//windows cpu temperature
function win_cpu_temp(){
$wmi = new COM("winmgmts://./root\WMI");
$cpus = $wmi->execquery("SELECT * FROM MSAcpi_ThermalZoneTemperature");
foreach ($cpus as $cpu) {
$cpupre = $cpu->CurrentTemperature;
}
$cpu_temp = ($cpupre/10)-273.15 . ' C';
return $cpu_temp;
}
echo win_cpu_temp();
?>
My problem, is that the script displays 59.55 C which I had thought was correct. I checked this value several hours later, and it's exactly the same. I just put the CPU to work at 90% compressing video for ten minutes, and this value is the same still.
Can anyone help me find the "true" value for this function?
I've read (to no avail):
MSAcpi_ThermalZoneTemperature class not showing actual temperature
How is, say, "Core Temp" getting its values? Same computer, it reports between 49 and 53 Celsius.

Answer 1

With a little digging around I found the common issue with using MSAcpi_ThermalZoneTemperature was that it is dependent upon being implemented on your system.
You could try querying Win32_TemperatureProbe and see if you have any luck there.
Neither MSAcpi_ThermalZoneTemperature or Win32_TemperatureProbe worked on my system, although if you have admin access, you can use http://openhardwaremonitor.org/ which provides a WMI interface for all available sensor data.
This worked great for me and I was able to accurately report CPU Core temp from a PHP script:
function report_cpu_temp(){
$wmi = new COM('winmgmts://./root/OpenHardwareMonitor');
$result = $wmi->ExecQuery("SELECT * FROM Sensor");
foreach($result as $obj){
if($obj->SensorType == 'Temperature' && strpos($obj->Parent, 'cpu') > 0)
echo "$obj->Name ($obj->Value C)"; // output cpu core temp
else
echo 'skipping ' . $obj->Identifier ;
echo '<br />';
}
}
Hope this helps.