Conjugate Gradient and OpenCL

I've just finished a conjugate gradient implementation for OpenCL. It has not performance yet, but I'm working on this to fix the bugs and/or optimize the code.

Here you are a PDF that makes an overview on the subject.

Nvidia's Next Generation: Fermi - key architectural highlights

Third Generation Streaming Multiprocessor (SM)

• 32 CUDA cores per SM, 4x over GT200
• 8x the peak double precision floating point performance over GT200
• Dual Warp Scheduler simultaneously schedules and dispatches instructions from two independent warps
• 64 KB of RAM with a configurable partitioning of shared memory and L1 cache

Second Generation Parallel Thread Execution ISA

• Unified Address Space with Full C++ Support
• Optimized for OpenCL and DirectCompute
• Full IEEE 754-2008 32-bit and 64-bit precision
• Full 32-bit integer path with 64-bit extensions
• Memory access instructions to support transition to 64-bit addressing
• Improved Performance through Predication

Improved Memory Subsystem

• NVIDIA Parallel DataCache™ hierarchy with Configurable L1 and Unified L2
• Caches
• First GPU with ECC memory support
• Greatly improved atomic memory operation performance

NVIDIA GigaThread™ Engine

• 10x faster application context switching
• Concurrent kernel execution
• Out of Order thread block execution
• Dual overlapped memory transfer engines

more information: http://www.nvidia.com/content/PDF/fermi_white_papers/NVIDIA_Fermi_Compute_Architecture_Whitepaper.pdf

ATI Stream Software Development Kit (SDK) v2.0 Beta Program

What’s New in v2.0-beta4

• First beta release of ATI Stream SDK with OpenCL™ GPU support.
• ATI Stream SDK v2.0 OpenCL™ is certified OpenCL™ 1.0 conformant by Khronos.
• Added Microsoft® Windows® 7 support.
• Added native Microsoft® Windows® 64-bit support.
• Float comparisons in kernels no longer produce a runtime error.
• Various other issues from previous v2.0 beta releases have been resolved.

More information: http://developer.amd.com/GPU/ATISTREAMSDKBETAPROGRAM/Pages/default.aspx

OpenCL BLAS - Makefile for MAC

Thanks to Mario Rometsch for a version of OpenCL BLAS Makefile for MacOS. You can download it on the SourceForge.

OpenCL BLAS Makefile for MacOS

BLAS Library for OpenCL

I use the conjugate gradient solver without preconditioners to solve a linear system Ax=b, where A is a sparse matrix. This method is iterative and uses some BLAS functions like Dot Product, Scalar Product, xAXPY and xGEMV (SpMV for sparse matrix).I've started to develop these functions for the OpenCL language and I've decided to share them.

Right now, the following BLAS level 1 functions are available:
sDOT :: single precision dot product or scalar product (dot<-xy)
sNRM2 :: single precision vector 2-norm
sSCAL :: single precision product of vector by scalar (x<-ax)
sAXPY :: single precision AXPY (y<-ax + y) You can download the OpenCL code which was tested on NVIDIA Tesla C870 and GPU Computing SDK 2.3

SourceForge Project

Please join up with your contribution!

Update: OpenCL BLAS now is a discontinued project.

ATI Stream Software Development Kit (SDK) v2.0 Beta Program With OpenCL™ 1.0 Support

With ATI Stream SDK, AMD/ATI provides a way to program OpenCL on its cards. I didn't download it yet, but you can get more information on:

http://developer.amd.com/GPU/ATISTREAMSDKBETAPROGRAM/Pages/default.aspx

and on the OpenCL/ATI forum:
http://forums.amd.com/devforum/categories.cfm?catid=390&entercat=y

I'm going to test it and I will post here an overview.

GPU and Matlab

If you like programming Matlab-like environment, I suggest the freeware GPUMat from GP-you Group. You can explore the power of GPUs, BLAS and FFT libraries on NVIDIA cards. You can get more information on:
GP-you Group