AMD Device Showing CPU Properties in clGetDeviceInfo

Question

I have an AMD w7000 firepro Card installed. When i query its properties, instead of showing its own properties, it just shows the same properties as that of my CPU (Intel Xeon), with the exception of 3 properties, as shown : 1.cl_global_mem_cache_size 2.cl_max_threads_per_block.

the way i query properties is i send the cl_device_id of all devices i find to a function get_prop(cl_device_id id) where i simply print all properties using clGetDeviceinfo.

PLATFORM 1: NAME : Intel(R) OpenCL num of devices in platform : 1 DEVICE=Intel(R) Xeon(R) CPU X5660 @ 2.80GHz

ADDRESS BITS:64
DEVICE GLOBAL MEM CACHE SIZE=262144
DEVICE GLOBAL MEM SIZE IN BYTES=25122017280
LOCAL MEM SIZE=32768
MAX CLOCK FREQUENCY=2800
NO. OF PARALLEL COMPUTE UNITS LIKE SMs=24
MAX THREADS IN ONE BLOCK=8192
MAX THREAD DIMENSIONS=3
OPENCL VERSION=OpenCL C 1.2 
MAX THREADS IN EACH DIMENSION=8192      8192    8192





PLATFORM 2:
NAME : AMD Accelerated Parallel Processing
num of devices in platform : 1
DEVICE=Intel(R) Xeon(R) CPU           X5660  @ 2.80GHz

ADDRESS BITS:64
DEVICE GLOBAL MEM CACHE SIZE=32768
DEVICE GLOBAL MEM SIZE IN BYTES=25122017280
LOCAL MEM SIZE=32768
MAX CLOCK FREQUENCY=2792
NO. OF PARALLEL COMPUTE UNITS LIKE SMs=24
MAX THREADS IN ONE BLOCK=1024
MAX THREAD DIMENSIONS=3
OPENCL VERSION=OpenCL C 1.2 
MAX THREADS IN EACH DIMENSION=1024      1024    1024

Can anyone explain why this is happening? fyk: im using AMDAPP SDK

Answer 1

You might have a mix-up between the device IDs, and possibly across different platforms. Are you sure that you are correctly capturing each device as a unique cl_device_id?

From your listing it appears that you have more than one platform installed; you have listed a "Platform: 2," so there must be a Platform: 1? If your not already handling this, capture the platform IDs into an array as well. Like this:

cl_uint nPlatforms;
cl_uint err = CL_SUCCESS;
err = clGetPlatformIDs(1, NULL, &nPlatforms);

So with multiple platforms (assuming your using C, I'll set it up with malloc, with C++ you can use "new" to create the platformID_Array):

cl_platform_id* platformID_Array = malloc(sizeof(cl_platform_id)*nPlatforms);
err = CL_SUCCESS;
err = clGetPlatformIDs(nPlatforms, platformID_Array, NULL);

And then for example, check the names:

for (cl_uint i = 0; i < nPlatforms; i++) {
    size_t vendorSize;
    char* vendorCstring;
    err = clGetPlatformInfo(platformID_Array[i], CL_PLATFORM_VENDOR, 0, NULL, &vendorSize);
    vendorCstring = (char*)malloc(sizeof(char)*vendorSize);
    err = clGetPlatformInfo(platformID_Array[i], CL_PLATFORM_VENDOR, vendorSize, vendorCstring, NULL);
    printf("Platform name = %s\n",vendorCstring);
}

Next you will then need two separate device arrays, one for each platform. Using a similar approach as above, loop through each device ID array and query the values for each device, for a given platform.