I am now programming on Android and I wonder whether we can use GPGPU for Android now? I once heard that Renderscript can potentially execute on GPGPU in the future. But I wonder whether it is possible for us to programming on GPGPU now? And if it is possible for me to program on the Android GPGPU, where can I find some tutorials or sample programs? Thank you for your help and suggestions.
Up till now I know that the OpenGL ES library was now accelerated use GPU, but I want to use the GPU for computing. What I want to do is to accelerate computing so that I hope to use some libraries of APIs such as OpenCL.
2021-April Update
Google has announced deprecation of the RenderScript API in favor of Vulkan with Android 12.
The option for manufacturers to include the Vulkan API was made available in Android 7.0 Compatibility Definition Document - 3.3.1.1. Graphic Libraries.
Original Answer
Actually Renderscript Compute doesn't use the GPU at this time, but is designed for it
From Romain Guy who works on the Android platform:
Renderscript Compute is currently CPU bound but with the for_each construct it will take advantage of multiple cores immediately
Renderscript Compute was designed to run on the GPU and/or the CPU
Renderscript Compute avoids having to write JNI code and gives you architecture independent, high performance results
Renderscript Compute can, as of Android 4.1, benefit from SIMD optimizations (NEON on ARM)
https://groups.google.com/d/msg/android-developers/m194NFf_ZqA/Whq4qWisv5MJ
yes , it is possible .
you can use either renderscript or opengGL ES 2.0 .
renderscript is available on android 3.0 and above , and openGL ES 2.0 is available on about 95% of the devices.
As of Android 4.2, Renderscript can involve GPU in computations (in certain cases).
More information here: http://android-developers.blogspot.com/2013/01/evolution-of-renderscript-performance.html
As I understand, ScriptIntrinsic subclasses are well-optimized to run on GPU on compatible hardware (for example, Nexus10 with Mali T604). Documentation:
http://developer.android.com/reference/android/renderscript/ScriptIntrinsic.html
Of course you can decide to use OpenCL, but Renderscript is guaranteed (by Google, being a part of Android itself) to be running even on hardware which doesn't support GPGPU computation and will use any other available acceleration means supported by hardware it is running on.
There are several options: You can use OpenGL ES 2.0, which is supported by almost all devices but has limited functionality for GPGPU. You can use OpenGL ES 3.0, with which you can do much more in terms of GPU processing. Or you can use RenderScript, but this is platform-specific and furthermore does not give you any influence on whether your algorithms run on the GPU or the CPU. A summary about this topic can be found in this master's thesis: Parallel Computing for Digital Signal Processing on Mobile Device GPUs.
You should also check out ogles_gpgpu, which allows GPGPU via OpenGL ES 2.0 on Android and iOS.
Related
I believe that openGL ES 3.2 (and 3.1 + Android Extensions Pack AEP) support it, but I've heard that some GPU's with previous versions (specifically 3.1 without AEP) also have this particular extension.
My question is: how can I tell which GPUs have that particular extension, enabling one to render to a float texture?
I've searched manufacturer sites, but haven't been able to find this info (maybe I'm looking in the wrong place?)
I'm also a little wary, I heard that one manufacturer added this ability in their driver... but I wonder if that is a software solution (and therefore much slower, defeating the purpose).
Further to this, of course it's possible to do the encoding decoding in your own shader - but wouldn't this incur significant overhead? Or, maybe it's fine?
[BTW: the reason I'm asking is I want to purchase a phone to play around with general-purpose computing on mobile GPUs, and the latest phones are much more expensive]
Many thanks for any help! I've been trying to find this on-and-off for months...
Float rendering support is mandatory in OpenGL ES 3.2. It is not required for OpenGL ES 3.0 / 3.1 / 3.1 + AEP.
For earlier implementations you want to use a platform exposing the EXT_color_buffer_half_float and/or EXT_color_buffer_float extension.
Note that floating point rendering is relatively expensive due to the additional bandwidth, even when supported natively in the hardware. For higher dynamic range consider using something like RGB10_A2 if you can, it's smaller and faster (and supported in 3.0 core).
Is RenderScript the only device-independent way to run GPGPU code on Android ?
I don't count Tegra as there is only few phones that have it.
RenderScript is the official Android compute platform. As a result it will be on all Android devices. It was designed specifically to address the problem of running one code base across many different devices.
Well, using RenderScript doesn't necessarily mean that your code will run on the GPU. It might also use the CPU and (hopefully) parallelize tasks on several CPU cores and use CPU vector instructions. But as far as I know, you can never be sure about that and the decision process is kind of a blackbox.
If you want to make sure that your code runs on the GPU, you can "simulate" some GPGPU functions with OpenGL ES 2.0 shaders. This will run on all devices that support OpenGL ES 2.0. It depends on what you want to do, but for example many image processing functions can be implemented very efficiently this way. There is a library called ogles_gpgpu that provides an architecture for GPGPU on Android and iOS systems: https://github.com/internaut/ogles_gpgpu
OpenGL ES 3.1 also supports "Compute Shaders" but few devices support this, yet.
Renderscript is an Android computation engine that lets you use CPU/GPU native hardware acceleration in order to boost applications, for example in image processing and computer vision algorithms.
Is there a similar thing in iOS and Windows Phone 7/8?
The RenderScript compatibility library is designed to compile for most any posix system. It would be very easy to get it running on other platforms.
I can't speak for Windows Phone but on iOS it would be vImage running on the Accelerate Framework. Just like Renderscript, it is dynamically optimized for the CPU on the target platform.
vImage optimizes image processing by using the CPU’s vector processor.
If a vector processor is not available, vImage uses the next best
available option. This framework allows you to reap the benefits of
vector processors without the need to write vectorized code.
https://developer.apple.com/library/mac/documentation/performance/Conceptual/vImage/Introduction/Introduction.html
I can't speak for Windows Phone but on iOS it would be Apple Metal, its language specification being almost same as renderscript c99.
For iOS it is the newly introduced swift I guess.
Maybe it is worth to try it out, but I'm not an iOS developer so I can't say anything about its performance, but the demos on the WWDC looked promising. Also instead of Renderscript Swift seemes to be designed for graphics, the Renderscript soppurt for graphics has been deprecated and Renderscript turned more into a general computation framework (which of course can be used as a backend for graphic calculations).
https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/TheBasics.html
Are there any Android devices where renderscript executes on the GPU instead of the CPU, or is this something not yet implemented anywhere?
As of JellyBean 4.2 there is a direct GPU integration for renderscript. See this and this.
I cannot confirm with any official documentation for Google, but I work with RenderScript all day every day and each time I run it, I see the logcat report loading drivers for graphics chips in my devices, most notably Tegra 2. Google has really lagged in documenting RenderScript, and I would not at all be surprised if they simply havn't corrected this omission in their discussion.
Currently the compute side of Renderscript will only run on the CPU:
For now, compute Renderscripts can only take advantage of CPU cores, but in the future, they can potentially run on other types of processors such as GPUs and DSPs.
Taken from Renderscript dev guide.
The graphics side of Renderscript sits on top of OpenGL ES so the shaders will run on the GPU.
ARM's Mali-T604 GPU will provide a target for the compute side of Renderscript (in a future Android release?) (see ARM Blog entry).
The design of RenderScript is so that it runs on the GPU. This was the main purpose of adding the new language. I assume there are devices where it runs on the CPU due to lack of support, but on most devices it runs on the GPU
I think this may depend on whether you're doing graphics or compute operations. The graphics operations will likely get executed on the GPU but the compute operations won't as far as I understand.
When you use the forEach construct the computation will run in multiple threads on the CPU, not the GPU (you can see this in the ICS source code). In future releases this may change (see https://events.linuxfoundation.org/slides/2011/lfcs/lfcs2011_llvm_liao.pdf) but I haven't seen any announcements.
Currently, only the Nexus 10 seems to support Renderscript GPU compute.
So Android 3.0 (honeycomb) is out now and boasts some kind of new hardware-accelerated 3D graphics engine called Renderscript.
Renderscript 3D graphics engine
Renderscript is a runtime 3D framework that provides both an API for building 3D scenes as well as a special, platform-independent shader language for maximum performance. Using Renderscript, you can accelerate graphics operations and data processing. Renderscript is an ideal way to create high-performance 3D effects for applications, wallpapers, carousels, and more.
And according to this blog post dating back from 2009, this graphics engine could already be found used in a class named Fountain (even before honeycomb). This last clue was helpful to me, because now I can easily find that class name in the Honeycomb code.
Can any of you supply any more insights into Renderscript? and ways to learn more about how to use it? Now that this has become a public api, I'm assuming that the people in-the-know may be able to get the permission to freely talk about it (I hope).
RenderScript is several things:
- A language, similar to C99 with extra advanced features. It's pre-compiled on the host and re-compiled on the device, to achieve best performance.
- A rendering library (you can draw textured meshes, etc.)
- A compute library (to run heavy computations in RenderScript which can then be offloaded to the GPU, several CPUs or DSPs.)
Have you downloaded the Honeycomb SDK via the android tool? It downloads documentation, including the javadoc pages for Renderscript.