I know Nvidia has CUDA, but what does ATI have? I dont want to use OpenCL because I want to keep as low level to the hardware as possible.
Is it brook, or stream?
The documentation available is pretty pathetic! CUDA seems easy to get programming, but I want to use ATI specifically because of their hardware.
OpenCL is AMD's currently preferred GPU/compute language.
Brook is deprecated.
However, you can write code at a very low level, using AMD's
shader and kernel analyzer
http://developer.amd.com/tools/shader/Pages/default.aspx.
http://developer.amd.com/tools/AMDAPPKernelAnalyzer/Pages/default.aspx
E.g. http://developer.amd.com/tools/shader/PublishingImages/GSA.png
shows OpenCL code, and the Radeon 5870 assembly produced.
You can actually code directly in several forms of "assembly".
Or at least you could - the webpages no longer mention this.
(I used to have this installed for tuning and testing, but do not at the moment.)
More usually, you can code in any of several forms of AMD IL, Intermediate Language,
which is closer to the machine than OpenCL. The kernel analyzer web page says
"If your kernel is an IL kernel Stream, KernelAnalyzer will automatically compile the IL..."
I would recommend that you use OpenCL, and then look at the disassembly and tweak the OpenCL code to be better tuned. But you can work in IL, and probably still can work at an even lower level.
Related
I am interested in how OpenCL memory transferring functions operate underneath (migration, reading/writing the buffer, mapping/unmapping). I could not find any open source implementation for OpenCL (for me Intel's one could be fine) and just explanations in the documentation don't give me any idea what is happening, for example, when I call clEnqueueMigrateMemObjects: what calls happen during this migration, what modules are active, how this migration happens, what mechanisms it uses underneath, does it use some cache mechanisms.
Is there a good source to read about it?
I am now exploring how OpenCL passes data to FPGAs. Xilinx currently uses native OpenCL implementation, present on a machine, plus some extensions.
If you're looking for low-level information (how a particular implementation implements those calls), probably the only source is the implementation.
There are a few opensource OpenCL on GPU implementations:
Raspberry Pi 3 (beta): https://github.com/doe300/VC4CL
OpenCL on Vulkan (beta): https://github.com/kpet/clvk
Mesa Clover (supports only 1.1): https://cgit.freedesktop.org/mesa/mesa/log/?qt=grep&q=clover
AMD ROCm: https://github.com/RadeonOpenCompute/ROCm-OpenCL-Runtime
Intel sources of NEO (their new OpenCL implementation) here: https://github.com/intel/compute-runtime
I'm not aware of Xilinx providing sources for their implementation, so if you want to know what exactly happens on Xilinx, your best chance is probably to ask on Xilinx forums or via some official support.
I have been through the documentation and didn't get a clear detailed description about UMat; however I think it has something to relate with GPU and CPU. Please help me out.
Thank you.
Perhaps section 3 of this document will help: [link now broken]
https://software.intel.com/sites/default/files/managed/2f/19/inde_opencv_3.0_arch_guide.pdf
Specifically, section 3.1:
A unified abstraction cv::UMat that enables the same APIs to be implemented using CPU or OpenCL code, without a requirement to call OpenCL accelerated version explicitly. These functions use an OpenCL-enabled GPU if exists in the system, and automatically switch to CPU operation otherwise.
and section 3.3:
Generally, the cv::UMat is the C++ class, which is very similar to cv::Mat. But the actual UMat data can be located in a regular system memory, dedicated video memory, or shared memory.
Link to usage suggested in the comments by #BourbonCreams:
https://docs.opencv.org/3.0-rc1/db/dfa/tutorial_transition_guide.html#tutorial_transition_hints_opencl
So I have a GPU memory leak in certain scenarios in my application. However, I am not aware of any detailed memory profiler for the GPU like those for the CPU. Are there anything out there that can achieve this? I am using D3D (since its WPF, there are d3d9, d3d10, d3d11 components...)
Thanks!
Are you using the debug setting in Dx control panel? This helps you dump the id of the leaking allocation. You can then proceed to set a HKLM registry value and break on the leaking allocation, as is explained here:
http://legalizeadulthood.wordpress.com/2009/06/28/direct3d-programming-tip-5-use-the-debug-runtime/
http://www.gamedev.net/topic/313718-tracking-down-a-directx-leak/
You can also try NSight, which you can download for free from NVidia. For Maximus cards there is also a specific GPU Debugger, and otherwise you can use the Graphics Debugger and try to isolate the memory bump there. In the Performance Debugger you can detect both OpenGl and DirectX events, though this is more performance oriented.
Depending on your GPU's vendor (As you have not provided us with the information), here are the possible solutions:
Intel: Use the Intel Media SDK 's GPU Utilization Utility. This comes packaed in the Intel INDE (Integrated Developer Environment).
AMD: CodeXL provides an on-the-fly debugger and an extensive memory profiling tool, and is now provided as part of their GPUOPen initiative.
NVIDIA: Use the Nvidia Visual Profiler (NVVP) combined with traces from Nvidia Nsight, and these utilities are provided with the standard Nvidia CUDA installer.
Notes:
With Nvidia, you must also install the provided GPU driver (~from the CUDA SDK) to enable any form of GPU-based driver profiling and debugging. Take note of the above limitation if you use your development rig for other purposes such as gaming, as the bundled driver is often much, much older than the stock, Game-ready drivers.
Thanks and regards,
Brainiarc7.
I'm working on a project that will use an AMD GPU for processing data. I noticed AMD has two different SDKs available on their website for using the GPU: ATI Stream Technology and
OpenCL™ and the AMD APP SDK. It looks like both support OpenCL but I haven't found anything on the site explicitly pointing out why one would use one over the other. What's the difference between these two?
The AMD APP SDK is here: http://developer.amd.com/sdks/AMDAPPSDK/Pages/default.aspx
The website should also answer your question about the difference between Stream and APP:
AMD Accelerated Parallel Processing (APP) SDK (formerly ATI Stream)
It used to be called AMD Stream SDK, they probably renamed it after adding support for non-Firestream hardware (namely OpenCL)
stream is the higher level amd-specific project (hardware and software) that includes opencl as the current software implementation. stream originally used the "brook" language, but switched to opencl in 2011. since then opencl became more popular (because it is a cross-platform standard that has been particularly well supported by apple) and these days amd doesn't seem to mention stream much. you can see this in a link like http://www.amd.com/us/products/technologies/stream-technology/opencl/pages/opencl.aspx where opencl is a "child" of stream (or the menu on the left of that page, where the higher level group is stream; other children are related to hardware).
in short, you want opencl. and despite the confusing mess that is amd's site, their opencl implementation is pretty solid.
hmmm. re-reading your question you seem to say there are two separate sdks. do you actually drill down to two different packages? my understanding is that opencl is the stream sdk. if you have found two different sdks (that are both current) can you link to them?
I'm completely new to OpenCL and GPU programming in general. Right now I am working on a project where I'm trying to see the performance saves that making use of the GPU in a game has. With this, however, I have ran into a snag; how do I set up my Directx project to speak to the OpenCL code base?
I've been googling this for about a week and haven't been able to find anything. If someone could point me in the right direction, I would be greatful.
OpenCL does not have anything to do with DirectX, it's simply another library.
For OpenCL you'll need an implementation ('SDK'), as Khronos don't provide those (they only provide the specifications).
Intel, AMD and Nvidia all provide one, but they have different requirements and limitations. See here for some of the existing implementations
After installing one of these, you'll have the necessary headers and libraries to code against the OpenCL API and link with OpenCL.dll
There are lots of sample sources in the SDKs or online, you have to write the kernel, the rest is mostly boilerplate code for initialization and kernel compilation.
The specific OpenCL extension that allows sharing of OpenCL buffers as textures and vice versa is cl_khr_d3d10_sharing.txt. http://www.khronos.org/registry/cl/extensions/khr/cl_khr_d3d10_sharing.txt
OpenCL has extensions for sharing memory between DirectX and OpenCL (and also between OpenGL and OpenCL.) This allows you to read or write DirectX buffers, including textures from within OpenCL. Ani's answer mentioned the extension for DirectX 10, but since the question is about DirectX 9, the extension you'll actually be using is cl_khr_dx9_media_sharing.
This extension has just 4 functions:
clGetDeviceIDsFromDX9MediaAdapterKHR
This function allows you to get the OpenCL device IDs of the OpenCL device(s) that can share memory with a given Direct3D 9 device.
clCreateFromDX9MediaSurfaceKHR
This function gets an OpenCL cl_mem memory object for a given Direct3D 9 memory object.
clEnqueueAcquireDX9MediaSurfacesKHR
This function locks the specified shared memory object so that you can read and/or write to it from OpenCL.
clEnqueueReleaseDX9MediaSurfacesKHR
This function unlocks the specified memory object from OpenCL, so that Direct3D can read/write it again.
Once you've used the above functions to share and synchronize access to the memory buffers, everything else on both the Direct3D 9 side and the OpenCL side works as it would otherwise with those particular APIs.
Note that your GPU will need to support the cl_khr_dx9_media_sharing extension in order for this to work. You can check the extensions property of the OpenCL platform and device in order to confirm that this extension is supported.
Some NVidia GPUs support a different extension instead, called cl_nv_d3d9_sharing. The basic idea of how it works is the same as with the cl_khr_dx9_media_sharing extension, but the exact details are a bit different. The biggest difference is just that it has different functions for getting cl_mem objects for different types of Direct3D 9 buffers, rather than just one function to cover all of them.