ISSN 2321 3361 © 2021 IJESC Research Article Volume 11 Issue No.05 An Analysis of Recent Applications of Multiple Instruction Multiple Data (MIMD) Computer Dosti Kh. Abbas Faculty of Engineering, Soran University, Kurdistan, Iraq Soran, Erbil, Kurdistan Regional, Iraq Abstract: MIMD means Multiple Instruction Multiple Data, which is an Architecture to acquire parallelism. It has been an interesting subject for many researchers in the past and recent years. To boost the computer performance, multiple instructions processes on multiple data. MIMD architecture works with distributed memory programming design and shared memory programming design. Each of the models has its benefits and drawbacks. MIMD computer architecture has been an interesting subject for many researchers in the past and recent years. In the literature, many studies have been done and different applications implemented on both of the architectures of MIMD computer devices. Nowadays, the architecture of parallel computers is improved from most angles. But, it still requires researches and testing applications on different kinds of its architecture. Our objective in this article review is to collect and review some works that have been done on MIMD architecture to evaluate and analyze the outcomes of the reviewed researches. Keywords: MIMD, Computer Parallel architecture, Shared Memory, Distributed Memory. I. INTRODUCTION was a group-based multiprocessor with an appropriated memory and a non-uniform access time. The nonappearance The requirement for increment in computer frameworks of stores and a long distant access inertness made information performance cannot be over-estimated, as it improves the arrangement basic. A large number of the thoughts in these processing of instructions. Parallel processing [1] is an multiprocessors would be reused during the 1980s when the approach in which instruction and data are operated at the microchip made it a lot less expensive to fabricate same time through computer devices. This technique works by multiprocessors. With the essential special case of the parallel partitioning huge issues into more modest parts which are then vector multiprocessors and all the more as of late of the IBM settled all the while. In a perfect world, it makes instruction Blue Gene model, any remaining ongoing MIMD computers execution quicker since there are numerous processors process have been worked from off-the-rack microchips utilizing on the program, yet it's frequently hard to partition an logically central memory and a bus or a distributed memory instruction such that different CPUs can execute various and interconnection network. MIMD computer architecture segments without meddling with each other. Subsequently, it has been an interesting subject for many researchers in the has become a dominant paradigm in architecture that past and recent years. In the literature, many studies have been machines have multi-core processors. In the case of multi-core done and different applications implemented on both of the processors, the execution of instruction will happen at the architectures of MIMD computer devices. Nowadays, the same time by any processor.The processors hold the execution architecture of parallel computers is improved from most of instruction separately depending on their structure. In a angles. But, it still requires researches and testing applications taxonomy, Michael J. Flynn categorized architectures of a on different kinds of its architecture. Our objective in this parallel computer into four kinds depending on the number of article review is to collect and review some works that have data and instructions that they can hold at a time [2]. Our been done on MIMDs to evaluate and analyze the outcomes of focus here is on MIMD parallel architecture. MIMD is a the reviewed researches. The following of this study is multiprocessor design in which different sets of instruction are structured as follows. In section two, MIMD architecture and in operation simultaneous sly and each cycle brings instruction its types are presented. Some recent works that had been done at the same time independently and perform the procedure on on MIMD computer machines will be reviewed in section the instructions simultaneously on numerous CPUs. It is hard three. Section four contains the discussion of our study. to differentiate the primary MIMD multiprocessor. Finally, we conclude our study in section 5. Shockingly, the primary computer from the Eckert-Mauchly Corporation, for instance, had copy units to improve II. MIMD ARCHITECTURE accessibility. Two of the best-recorded multi processor projects were embraced during the 1970s at University of In the field of computing, the MIMD is a procedure utilized to Carnegie Mellon. The first of these was C.mmp, which accomplish parallelism. Those devices, which are utilizing comprised 16 PDP-11s associated with a crossbar switch to 16 MIMD, have some processors that function independently and memory units. It was among the main multiprocessors with in asynchronously. Different instructions on a different part of excess of a couple of processors, and it had a shared memory data may be executed by different processors at any time. programming model. A large part of the focal point of the MIMD structures might be utilized in various application exploration in the C.mmp project was on programming, fields, for example, computer-aided, modeling, simulation, particularly in the OS region. A later multiprocessor, Cm*, and communication switches. MIMD computers can be of two IJESC, May 2021 28011 http:// ijesc.org/ categories such as distributed memory and shared memory. Through sending messages, Each PE can communicate The categorization is depending on accessing memory by with others. MIMD processors. Distributed memory computers may have By providing all the processors their memory, this type of mesh interconnection or hypercube schemes. In contrast, the architecture bypasses the downsides of the architecture of the shared memory computers may be of the types of extended, shared memory. A processor may just access the memory that bus-based, or hierarchical [3]. The architecture of MIMD is straightforwardly associated with it. contains a set of tightly coupled, N-individual processors. A memory that is common to the entire of processors is included and it cannot be accessed directly by the other processors. 2.1 SHARED MEMORY MIMD structure works with two kinds of memory, shared memory is one of them. All Processing Elements (PE) share a typical memory address. Each handling component can get to any module through an interconnected network straightforwardly. They impart by composing into normal location space. PE's are independent yet they have a typical memory [4]. The structure of a shared memory MIMD is illustrated in fig. 1. Figure.2. Distributed Memory [4] III. MIMD ARCHITECTURE APPLICATIONS The parallel instructions coding is more convoluted than consecutively writing instruction. By using this technique, different models or different architectures can be beneficial for various applications, specifically MIMD. Now, it is based on the application’s features indicating which structure is more functional to make the application and selecting preferable parallel hardware to be utilized for the application. In this section, some research works that used MIMD computer architecture for some scientific applications are reviewed in different areas of software computing. Neural network is one of the most used and most proposed algorithms for learning and Figure.1. Shared Memory [4] training different software applications in different areas. In our article review, we reviewed two different articles that the Feature of Shared Memory MIMD architecture is MIMD was used in the researches for evaluating the neural analyzed as follow: networks and the architectures. In one of the research works • Creates a set of processors and memory modules. [5], Abbas proposed to use an MIMD architecture. The way • Any memory module can be directly accessed by any toward preparing neural networks on parallel structures was processor through an interconnection network. utilized to survey the exhibition of such countless parallel • A universal address space is outlined by the group of machines. The authors explored the usage of backpropagation memory modules that are shared between the processors. (BP) on the Alex AVX-2 coarse-grained MIMD machine. A A vital advantage of this design type is that it is extremely host–worker parallel usage was completed to prepare various simple to program since there exists no unequivocal models to train the NetTalk dictionary. At the first, they connections among processors with interchanges tended to developed a computational design utilizing a single processor through the worldwide memory store. to finish the learning cycle. Additionally, they created a connection model for the host–worker topology to compute the 2.1 DISTRIBUTED MEMORY connection. The two models were then used to forecast the The other type of MIMD architecture is distributed memory. performance of the machine when processors were utilized and In this kind of architecture, all Processing components have a comparison was carried out with the genuine estimated their own location space. They interact with one another performance of the implementation of the parallel architecture. through message passing. Each handling component is Their study results show that the two models can be utilized blocking or waiting for a message. A software