IGP of Ivy bridge can't be found by OpenCL SDK - opencl

Question

I have set up a IvyBridge platform for coding OpenCL program. My system is win7 64-bit, VS2010 as developement tools. There is one i7-3770k with a nVidia GTX560 on my PC. When I queried the devices of my system, I cann't find HD4000. I have checked my system driver for HD4000 by using this webpage: http://www.intel.com/p/en_US/support/detect/graphics. The report said "Current Driver Installed 8.15.10.2696". OpenCL SDK is the latest Intel SDK for OpenCL Application 2012 windows 64-bit downloaded from http://software.intel.com/en-us/articles/vcsource-tools-opencl-sdk/. The following is my code and the output.
I also noticed that the device name of CPU is very strange. By the way, I have connected the HD4000 device to a monitor since I found someone met the issue that failed to create a CL context. And now I can find HD4000 can be detected by GPU-Z tool after we connected a monitor to HD4000. So anyone can help me solve this problem?
#include "stdafx.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <CL/cl.h>
int _tmain(int argc, _TCHAR* argv[])
{
cl_platform_id *platforms;
cl_uint num_platforms;
cl_device_id *devices_cpu, *devices_gpu;
cl_uint num_devices;
char dev_name[40], dev_vendor[40], dev_version[40], dev_profile[40];
char plt_name[40], plt_vendor[40], plt_version[40], plt_profile[40];
clGetPlatformIDs(1, NULL, &num_platforms);
platforms = (cl_platform_id*) malloc(sizeof(cl_platform_id) * num_platforms);
clGetPlatformIDs(num_platforms, platforms, NULL);
for(int i = num_platforms - 1; i >= 0; i--)
{
clGetPlatformInfo(platforms[i], CL_PLATFORM_NAME, sizeof(plt_name),&plt_name,NULL);
clGetPlatformInfo(platforms[i], CL_PLATFORM_VENDOR, sizeof(plt_vendor),&plt_vendor,NULL);
clGetPlatformInfo(platforms[i], CL_PLATFORM_VERSION, sizeof(plt_version),&plt_version,NULL);
clGetPlatformInfo(platforms[i], CL_PLATFORM_PROFILE, sizeof(plt_profile),&plt_profile,NULL);
printf("\n\n\nPlatform #%d Info: \n\n", i);
printf("Platform: %s \n", plt_name);
printf("Vendor: %s \n", plt_vendor);
printf("Version: %s \n", plt_version);
printf("Profile: %s \n", plt_profile);
clGetDeviceIDs(platforms[i],CL_DEVICE_TYPE_CPU, 1, NULL, &num_devices);
devices_cpu = (cl_device_id *)malloc(sizeof(cl_device_id) * num_devices);
clGetDeviceIDs(platforms[i], CL_DEVICE_TYPE_CPU, num_devices, devices_cpu, NULL);
for(int j = 0 ; j < num_devices; j++)
{
clGetDeviceInfo(devices_cpu[j], CL_DEVICE_NAME, sizeof(dev_name), &dev_name, NULL);
clGetDeviceInfo(devices_cpu[j], CL_DEVICE_VENDOR, sizeof(dev_vendor), &dev_vendor, NULL);
clGetDeviceInfo(devices_cpu[j], CL_DEVICE_VERSION, sizeof(dev_version), &dev_version, NULL);
clGetDeviceInfo(devices_cpu[j], CL_DEVICE_PROFILE, sizeof(dev_profile), &dev_profile, NULL);
printf("\n\n\nCPU Device Info: \n\n");
printf("Name: %s \n", dev_name);
printf("Vendor: %s \n", dev_vendor);
printf("Version: %s \n", dev_version);
printf("Profile: %s \n", dev_profile);
}
clGetDeviceIDs(platforms[i],CL_DEVICE_TYPE_GPU, 1, NULL, &num_devices);
devices_gpu = (cl_device_id *)malloc(sizeof(cl_device_id) * num_devices);
clGetDeviceIDs(platforms[i],CL_DEVICE_TYPE_GPU, num_devices, devices_gpu, NULL);
for(int j = 0; j < num_devices; j++)
{
clGetDeviceInfo(devices_gpu[j], CL_DEVICE_NAME, sizeof(dev_name), &dev_name, NULL);
clGetDeviceInfo(devices_gpu[j], CL_DEVICE_VENDOR, sizeof(dev_vendor), &dev_vendor, NULL);
clGetDeviceInfo(devices_gpu[j], CL_DEVICE_VERSION, sizeof(dev_version), &dev_version, NULL);
clGetDeviceInfo(devices_gpu[j], CL_DEVICE_PROFILE, sizeof(dev_profile), &dev_profile, NULL);
printf("\n\n\nGPU Device Info: \n\n");
printf("Platform: %s \n", dev_name);
printf("Vendor: %s \n", dev_vendor);
printf("Version: %s \n", dev_version);
printf("Profile: %s \n", dev_profile);
}
free((void*)devices_cpu);
free((void*)devices_gpu);
}
return 0;
}
output:
Platform #1 Info:
Platform: Intel(R) OpenCL
Vendor: Intel(R) Corporation
Version: OpenCL 1.1
Profile: FULL_PROFILE
CPU Device Info:
Name: ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌIntel(R) Corporation
Vendor: Intel(R) Corporation
Version: OpenCL 1.1 (Build 31360.31441)
Profile: FULL_PROFILE
Platform #0 Info:
Platform: NVIDIA CUDA
Vendor: NVIDIA Corporation
Version: OpenCL 1.1 CUDA 4.2.1
Profile: FULL_PROFILE
GPU Device Info:
Platform: GeForce GTX 560 Ti
Vendor: NVIDIA Corporation
Version: OpenCL 1.1 CUDA
Profile: FULL_PROFILE

Answer 1

OpenCL does not work on HD4000 if there is no display connected to the card.
This is from my own testing and answers in Intel forums.
See these threads on Intel forums: 1 2 3.