Subdevice Support on Intel i5 Ivy Bridge

Hi all,

I am trying to divide my CPU into subdevices to solve a task parallel problem. Unfortunately I keep getting those CL_DEVICE_PARTITION_FAILED errors.

Here is what I tried:

    cl_platform_id platform_id = NULL;
    cl_device_id device_id = NULL;
    cl_device_id subdevice_id[4];
    cl_int ret;
    cl_uint ret_num_platforms;
    cl_uint ret_num_devices;
    // Get Platform and Device
    ret = clGetPlatformIDs(1, &platform_id, &ret_num_platforms);
    ret = clGetDeviceIDs(platform_id, CL_DEVICE_TYPE_CPU, 1, &device_id, &ret_num_devices);

    // Equally divide into two Subdevices with one execution unit each.
    cl_device_partition_property props[3] = {CL_DEVICE_PARTITION_EQUALLY, 1, 0};
    ret = clCreateSubDevices(device_id,
    // Did it work?

When I use clGetDeviceInfo to query for the OpenCL C Version of the CPU device I get “Open CL C 1.2”. So as far as I understand the specification subdevices should be supported. Nevertheless when I query for CL_DEVICE_PARTITION_MAX_SUB_DEVICES I get a 0. I am using an Intel i5-3427U CPU (shows 4 Execution Units), Mac OS X 10.9.2 and XCode 5.1. The CPU is the one that is build in the 13" Macbook Airs from 2012.

Am I missing something, or are subdevices just not supported on my CPU yet?

Any help appreaciated, thank you.