Algorithms and Parallel Computing

3.10 SM

A stream multiprocessor is a type of SIMD or a MIMD machine where the constituent processors are streaming processors (SPs) or thread processors. A stream processor is defined as a processor that deals with data streams, and its instruction set architecture (ISA) contains kernels to process these streams [32]. The concept of stream processing is closely associated with the graphics processing unit (GPU) where the GPU is thereby able to perform general compute-intensive general-purpose computations. The GPU thus becomes a general-purpose GPU. Examples of data streams are vectors of floating point numbers or a group of frame pixels for video data processing. This type of data shows temporal and spatial localities. Temporal locality is when the input data stream is used only a few times to produce the output steam. Spatial locality is when the input data stream is located in the same memory block. A successful example of a stream multiprocessor is the new generations of GPUs like Fermi from NVIDIA [33].

Applications suited for SM must satisfy three characteristics [34]:

1. Compute intensity

2. Data parallelism

3. Consumer–producer locality, that is, temporal and spatial locality

Compute intensity is defined as the number of arithmetic operations per I/O or global memory reference. In applications suitable for stream processing, this ratio could reach 50:1 and above. Data parallelism is when the same operation is performed on all data in an input stream in parallel. Producer–consumer ...