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memorysizeopencllocal
user3617694
user3617694

Reputation: 153

How To Calculate OpenCL Memory Max Limit

Does anyone know how to measure maximum limit or allow range size for constant,local.private,global memory

i use gpu caps viewer tool for cl info and get the result

https://www.dropbox.com/s/lb1y94njg5y37jv/4.jpg

Global memory = 2048 MB,
Local  memory =32 KB,
constant memory =64 KB,

is that means maximum memory size

the open-cl device info https://www.dropbox.com/s/2fr827ikcrjvoe0/new%20%204.txt

Upvotes: 1

Views: 1654

Answers (2)

Kyle Lutz
Kyle Lutz

Reputation: 8046

This is fairly easy using the Boost.Compute C++ wrapper library for OpenCL:

// get the default device                                                                                                                                                                                                                
boost::compute::device device = boost::compute::system::default_device();

// print out memory sizes
std::cout << "device: " << device.name() << std::endl;
std::cout << "  global memory size: "
          << device.get_info<cl_ulong>(CL_DEVICE_GLOBAL_MEM_SIZE) / 1024 / 1024
          << " MB"
          << std::endl;
std::cout << "  local memory size: "
          << device.get_info<cl_ulong>(CL_DEVICE_LOCAL_MEM_SIZE) / 1024
          << " KB"
          << std::endl;
std::cout << "  constant memory size: "
          << device.get_info<cl_ulong>(CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE) / 1024
          << " KB"
          << std::endl;

Which will print something like this:

device: Tahiti
  global memory size: 2511 MB
  local memory size: 32 KB
  constant memory size: 64 KB

See the memory_limits.cpp example for the full source code.

Upvotes: 0

DarkZeros
DarkZeros

Reputation: 8420

Query the device properties with clGetDeviceInfo() OpenCL Doc

The values you want are:

Global - CL_DEVICE_GLOBAL_MEM_SIZE - Total maximum mem size the device can hold
Local - CL_DEVICE_LOCAL_MEM_SIZE - Local group temporal shared max mem size
Constant - CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE - Constant arguments max mem size

Private is impossible to query, and depends on many things like the code and work size, just use as little as you can.

Upvotes: 1

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