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[takercena]

Based on these code, OpenCL report 2046 devices on AMD platform. What happen?

    int ctr = 0;
    cl_uint selectedPlatform = 0;
    char param[50];
    for(ctr; ctr < num_platforms; ctr++)
    {
        clGetPlatformInfo(platforms[ctr], CL_PLATFORM_VENDOR, sizeof(param), &param, NULL);
        printf("%s\n", param);
        if(strncmp(param, "NVIDIA", 6) == 0)
        {
            printf("nVidia\n");
            selectedPlatform = ctr;
        }
        else if (strncmp(param, "Advanced", 😎 == 0)
        {
            printf("Advanced Micro Devices\n");
            clGetDeviceIDs(platforms[ctr], CL_DEVICE_TYPE_ALL, 5, NULL, &num_devices);
            printf("Consist of %d OpenCL devices\n", num_devices); 
        }
        else if (strncmp(param, "Intel", 5) == 0)
        {
            printf("Intel\n");
        }
    }

[gbilotta · Accepted solution]

What is happening is that in

clGetDeviceIDs(platforms[ctr], CL_DEVICE_TYPE_ALL, 5, NULL, &num_devices); 

you are asking at the same time for the name of 5 devices (not to be stored anywhere) and for the number of devices, and this probably confuses the OpenCL implementation, so that num_devices is not properly initialized or getting a bogus value. Try using 0 instead of 5 as third parameter.

The specification is not explicit on this, but I see no reason why num_devices should not be correctly initialized even when num_entries is present, which is why I think this is a bug in the implementation.

[takercena]

Yea, that fixed it.