Windows CPU frequency

windows_cpu_freq.cpp

#include <windows.h>
#include <ntstatus.h>
#include <powerbase.h>
#include <stdio.h>

#include <vector>

#pragma comment(lib, "powrprof.lib")

typedef struct _PROCESSOR_POWER_INFORMATION {
    ULONG Number;
    ULONG MaxMhz;
    ULONG CurrentMhz;
    ULONG MhzLimit;
    ULONG MaxIdleState;
    ULONG CurrentIdleState;
} PROCESSOR_POWER_INFORMATION, *PPROCESSOR_POWER_INFORMATION;

int main(int argc, char *argv[]) {
    SYSTEM_INFO sys_info{};
    GetSystemInfo(&sys_info);

    std::vector<PROCESSOR_POWER_INFORMATION> ppi(sys_info.dwNumberOfProcessors);
    DWORD bufferSize = ppi.size() * sizeof(ppi[0]);
    NTSTATUS status = CallNtPowerInformation(ProcessorInformation, NULL, 0, ppi.data(), bufferSize);

    if (status != STATUS_SUCCESS) {
        printf("Failed to get CPU frequency\n");
        return EXIT_FAILURE;
    }

    int i = 0;
    for (const auto &item: ppi) {
        printf("CPU %d, max freq %ld mHz, cur freq %ld mHz, limit freq %ld mHz\n",
               i, item.MaxMhz, item.CurrentMhz, item.MhzLimit);
        i++;
    }

    return EXIT_SUCCESS;
}