How Can I Retrieve the CPU Core Count in .NET/C#?

Get the number of CPU cores in .NET/C#

Determining the number of CPU cores available to your application is critical to optimizing performance. In .NET/C#, there are multiple ways to extract this information:

1. Environment.ProcessorCount

This property provides the number of logical processors on the system. However, it does not differentiate between physical processors and hyper-threaded cores.

<code class="language-C#">Console.WriteLine("逻辑处理器数量: {0}", Environment.ProcessorCount);</code>

2. Win32_Processor

Using WMI (Windows Management Instrumentation) you can access more detailed information about the processor:

Physical Processor:

<code class="language-C#">foreach (var item in new System.Management.ManagementObjectSearcher("Select * from Win32_ComputerSystem").Get())
{
    Console.WriteLine("物理处理器数量: {0}", item["NumberOfProcessors"]);
}</code>

Number of cores:

<code class="language-C#">int coreCount = 0;
foreach (var item in new System.Management.ManagementObjectSearcher("Select * from Win32_Processor").Get())
{
    coreCount += int.Parse(item["NumberOfCores"].ToString());
}
Console.WriteLine("核心数量: {0}", coreCount);</code>

3. Excluded processors

Additionally, you can use Windows API calls to discover excluded processors in Windows. The following code displays the total number of logical processors, including excluded processors:

<code class="language-C#">int deviceCount = 0;
IntPtr deviceList = IntPtr.Zero;
Guid processorGuid = new Guid("{50127dc3-0f36-415e-a6cc-4cb3be910b65}");

try
{
    deviceList = SetupDiGetClassDevs(ref processorGuid, "ACPI", IntPtr.Zero, (int)DIGCF.PRESENT);
    for (int deviceNumber = 0; ; deviceNumber++)
    {
        SP_DEVINFO_DATA deviceInfo = new SP_DEVINFO_DATA();
        deviceInfo.cbSize = Marshal.SizeOf(deviceInfo);
        if (!SetupDiEnumDeviceInfo(deviceList, deviceNumber, ref deviceInfo))
        {
            deviceCount = deviceNumber;
            break;
        }
    }
}
finally
{
    if (deviceList != IntPtr.Zero) { SetupDiDestroyDeviceInfoList(deviceList); }
}
Console.WriteLine("核心数量: {0}", deviceCount);</code>

The above is the detailed content of How Can I Retrieve the CPU Core Count in .NET/C#?. For more information, please follow other related articles on the PHP Chinese website!