Question

I’m trying to create a function that returns frequency of IOS device’s processor. The code I am using always returns zero. Where am I going wrong?

-(void) printProcessorInfo 
{
    size_t length;
    int mib[6]; 
    int result;

    printf("Processor Info\n");
    printf("--------------\n");

    mib[0] = CTL_HW;
    mib[1] = HW_CPU_FREQ;
    length = sizeof(result);
    if (sysctl(mib, 2, &result, &length, NULL, 0) < 0)
    {
        perror("getting cpu frequency");
    }
    printf("CPU Frequency = %d hz\n", result);

    mib[0] = CTL_HW;
    mib[1] = HW_BUS_FREQ;
    length = sizeof(result);
    if (sysctl(mib, 2, &result, &length, NULL, 0) < 0)
    {
        perror("getting bus frequency");
    }
    printf("Bus Frequency = %d hz\n", result);
    printf("\n");
}

Thanks

Answer 1

The code is OK — iOS doesn’t return the CPU freq for some (or possibly all) devices. E.g., I think the clock rate of the Apple A4 in the iPod 4th gen devices is still unknown.

The best you can do is estimate the clock rate.