CSC/ECE 506 Spring 2011/ch2a mc

Introduction

The Graphical Processing Unit (GPU) is a dedicated super-threaded, massively data parallel co-processor. Unlike the CPU, GPUs are designed to be highly parallel, have a high computational throughput, and high memory throughput. CPUs are architected to perform well for single and multi-threaded applications. A number of programming APIs have been introduced to allow programmers to harness the power of the GPU to perform parallel tasks. Two such architectures are OpenCL and Compute Unified Device Architecture (CUDA).

Compute Unified Device Architecture (CUDA)

CUDA is one of the parallel architectures available to modern GPUs. CUDA a proprietary architecture developed by NVIDIA. CUDA was introduced with NVIDIA’s GeForce 8, February 2007, series of video cards. This architecture gives programmers access to the GPUs multicore processor for performing math intensive operations. These operations include physics modeling (PhysX), physical modeling, image processing, matrix algebra, etc. These GPUs are specifically design to perform many floating point and integer operations simultaneously. CUDA is capable of handling millions of threads simultaneously with little overhead to manage this large number of threads.

CUDA Architecture

Figure 1 shows the typical arrangement on for a GPU multiprocessor. This figure shows the general flow path of data through the GPU. Data flows from the host to the thread execution manager, which spawns and schedules the threads to each stream processor (SP). Each multi-processor, in this figure, contains eight stream processors. Each stream processor has its own memory, texture filter (TF). Each pair of processors has a shared L1 cache. Global memory is a shared memory is shared amongst all the stream processors.