To get the cpu speed in C# and VB.NET you can use the following snippet.

Sample C#

public uint GetCpuSpeed()
{
  var managementObject = new ManagementObject("Win32_Processor.DeviceID='CPU0'");
  var speed = (uint)(managementObject["CurrentClockSpeed"]);
  managementObject.Dispose();
  return speed;
}

Sample VB.NET

Public Function GetCpuSpeed() As UInteger
	Dim managementObject = New ManagementObject("Win32_Processor.DeviceID='CPU0'")
	Dim speed As UInteger = CUInt(managementObject("CurrentClockSpeed"))
	managementObject.Dispose()
	Return speed
End Function