How to get CPU frequency in c#

Question

How can I get in c# the CPU frequency (example : 2Ghz) ? It's simple but I don't find it in the environnement variables. Thanks :)

Answer 1

If you want to get the turbo speed, you can make use of the "% Processor Performance" performance counter and multiply it with the WMI "MaxClockSpeed" as follows:

private string GetCPUInfo()
{
  PerformanceCounter cpuCounter = new PerformanceCounter("Processor Information", "% Processor Performance", "_Total");
  double cpuValue = cpuCounter.NextValue();

  Thread loop = new Thread(() => InfiniteLoop());
  loop.Start();

  Thread.Sleep(1000);
  cpuValue = cpuCounter.NextValue();
  loop.Abort();

  foreach (ManagementObject obj in new ManagementObjectSearcher("SELECT *, Name FROM Win32_Processor").Get())
  {
    double maxSpeed = Convert.ToDouble(obj["MaxClockSpeed"]) / 1000;
    double turboSpeed = maxSpeed * cpuValue / 100;
    return string.Format("{0} Running at {1:0.00}Ghz, Turbo Speed: {2:0.00}Ghz",  obj["Name"], maxSpeed, turboSpeed);
  }

  return string.Empty;
}

The InfiniteLoop method is simply an integer that gets 1 added and subtracted:

private void InfiniteLoop()
{
  int i = 0;

  while (true)
    i = i + 1 - 1;
}

The InfiniteLoop method is just added to give the CPU something to do and turbo in the process. The loop is allowed to run for a second before the next value is taken and the loop aborted.

Answer 2

One could take the information out of the registry, but dunno if it works on Windows XP or older (mine is Windows 7).

HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/CentralProcessor/0/ProcessorName 

reads like

Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz

for me.

Something like this code could retrieve the information (not tested):

RegistryKey processor_name = Registry.LocalMachine.OpenSubKey(@"Hardware\Description\System\CentralProcessor\0", RegistryKeyPermissionCheck.ReadSubTree);  


if (processor_name != null)
{
  if (processor_name.GetValue("ProcessorNameString") != null)
  {
    string value = processor_name.GetValue("ProcessorNameString");
    string freq = value.Split('@')[1];
    ...
  }
}

(source: here)

Answer 3

You can get it via WMI, but it's quite slow so if you're going to be getting it on more than one occasion I'd suggest you cache it - something like:

namespace Helpers
{
    using System.Management;

    public static class HardwareHelpers
    {
        private static uint? maxCpuSpeed = null;
        public static uint MaxCpuSpeed
        {
            get
            {
                return maxCpuSpeed.HasValue ? maxCpuSpeed.Value : (maxCpuSpeed = GetMaxCpuSpeed()).Value;
            }
        }

        private static uint GetMaxCpuSpeed()
        {
            using (var managementObject = new ManagementObject("Win32_Processor.DeviceID='CPU0'"))
            {
                var sp = (uint)(managementObject["MaxClockSpeed"]);

                return sp;
            }
        }
    }
}