细粒度和粗粒度SIMD体系结构之间的区别

SIMD代表单指令多数据实际上是Flynn分类中的一类并行计算机。它概述了具有多个处理元素的计算机，这些元素可以同时对多个数据点执行相同的操作。

而且，粒度是将系统分解为各个小部分的概念，我们可以说是系统本身或系统的描述/观察。当将较大的实体细分为各个部分时，它实际上是相关的。例如，一个地块被分成码，比说一个地块要精细得多。

SIMD(单指令多数据)可以分为多种类型，但SIMD的2种主要和最重要的类型是：

(i)细粒度的SIMD：
这些实际上是详细说明，涉及的是实际上很小的组件，实际上是由更大的组件组成的。

(ii)粗粒SIMD：
这些系统由较少的组件组成，这些组件显然比原始组件要多，但比细粒度SIMD小得多，但是组件的大小比系统的细粒度子组件要大得多(高/更大)。

细粒度和粗粒度SIMD体系结构之间的区别：

S.No.	Fine-Grained SIMD	Coarse-Grained SIMD
1.	Fine Grain SIMD have less computation time then the coarse grain architecture.	Coarse Grain SIMD have more computation time then the Fine grain architecture.
2.	Here, programs are broken into large number of small tasks.	Here, programs are broken into small number of large task.
3	Fine Grain SIMD have much higher level of parallelism then Coarse grain SIMD.	Coarse grain SIMD have lower level of parallelism then Fine Grain SIMD.
4.	Here, Grain Size is over 1000 instructions.	Here, Grain Size in range of 2-500 instructions.
5.	Here, the size of subcomponents is much smaller than the Coarse grained.	Here, the size of subcomponents is more than the Fine-Grained.
6.	Here, two types of parallelism can be obtained – a) Instruction Level Parallelism b) Loop Level Parallelism	Here, these two types of parallelism can be obtained – a) Sub-program b) Program Level Parallelism
7.	In Fine Grain SIMD, Load Balancing is proper.	In Coarse Grain SIMD, Load Balancing is improper.
8.	Here Parallelism can be detected using compiler.	Here Parallelism can’t be detected using compiler.
9.	Fine Grain SIMD is a much costlier process than the Coarse Grain SIMD.	Coarse Grain SIMD is much cheaper than the Fine Grain SIMD.
10.	Fine Grain is the concept of future multi-threaded architectures to be used in the future also.	Coarse Grain is in one of the earlier concepts of single-threaded architectures.
11.	The Detailed description is further divided into many small subcomponents and makes the processes less complex from the original one and from the coarse-grained also.	The Detailed description is divided into large subcomponents and makes the processes less complex than the original one but more complex than Fine-Grained.
12.	Examples – Connection Machine (CM-2), J-Machine, etc.	Examples – CRAY Y, etc.