There are many types of models and architecture that are introduced in the history of the computes. The symmetric multiprocessing (SMP) and master-slave multiprocessing (MSMP) are two of the types among the various architectures. These models completely differ with each other. In SMP every CPU has equal access to the resources while in MSMP the master computer has access to all the resources and manages the system while assigning the tasks to the slave computer, the slave processor is obliged to perform that task. Both can have the hyper threading. It means to do more than one task with one physical processor as the processor is divided into two or more logical processors.

In master slave multi processing (MSMP) all the computers are connected to a single powerful computer which manages all the operations and controls the resources and scheduling, this computer which has all the control is the master. The computer which asks a service from the master computer is known as the slave computers. The master computer gave the tasks to the slave computers. Slave computers can also ask for a service from the master computer. If any slave computer requests for the data kept in the memory then he has to contact to the administrator of the master computer. In this type of model the whole authority is with hold by the master computer and he can give access to any type of resources to any computer. Slaves execute data through master processor computer. The network of this system is simple and the data is also protected as everyone is not allowed to access the data. But it has some disadvantages too. They are that the master computer becomes the bottleneck and if it fails the whole system will be collapsed. (Multiprocessing System)

As in symmetrical multiprocessing (SMP) all the computers are given the authority to access the resources. The memory is shared among all the computers. Every computer has its own CPU and it determines itself what to do. Every CPU has the right to access any type of data from any computer in the networking. The I/O devices are also shared among the computers and any computer can use it. All the computers share their memory and they can also do changes in it. That’s why this type of model is not recommended where security is needed. The data can be accessed by any computer. Its advantage is that the networking traffic decreases which results in fast processing. Data is more reliable. If any fault came then it can be easily removed. As far as disadvantages, it has a complex implementation technique and resources may conflict with each other. As all the computers have access to the I/O devices so they may send requests to input or output devices simultaneously which can reduce the processing speed and may have to wait for a long time. As all the processors have access to input and output resources theses processors can execute data by themselves they don’t need the permission of any other computer like that of a master processor. (Irv, 2003)

Hyper threading technology which is abbreviated as HT or HTT is Intel's proprietary simultaneous multithreading (SMT). It is used to do two tasks at the same time. The minimum standard required for the hyper threading is the symmetric processor. The operating system should also be updated and it should know about hyper threading as if the symmetric computer has the hyper threading facility but the operating system does not support it then its logical processors will remain idle. If the SMP has 2 hyper threaded processors with this facility with a total of 4 logical processors but unless the system knows about it operating system will treat all the four processors as the same. The best part about simultaneously multi threading is that there is no special reason required by the O.S to use SMT. As long as the operating system is skilled enough of working with SMP processors, it will identify CPUs with hyper-threading potential as two times the number of objective processors. (Princton) As we talk about the Master Slave multiprocessing model it can also have the hyper threading option but it depends upon the master computer and the slave computers too. There are many types of master computer. (IEEEXplore, 2009)

MSMP i.e. the Master Slave Multiprocessor is suited for such applications which are logical or arithmetic. Like solving matrices or problems related to two dimension models. The master will order the tasks to the slaves such like a slave will be performing a calculation while the other slave will be rendering a 2D video. MSMP is best suited for such applications where the work load is well defined because in such system slaves would have less capability than the master systems. They are most effective when the number of processors is few. Currently there are no as much sales of such computers that use master slave multiprocessor designs. The master usually execute in kernel mode while the other processors that are working as slaves executes in user mode. Recently Globe et al established a MSMP system in which the master handle all system calls while the slave sends request to master when the process makes a system call. In DEC system 10 MSMP is used where there are two processors; one the master and other as a slave, the operating system runs on the master processor while the slave is treated as schedulable resource. (Jadhav, 2009)

The SMP type of architecture is mostly used for the applications used in science, business or industry. In these areas the SMP is used as they often use customized software for processing. The word processors and the computers games are also design in such a way that they can give the best graphics and its other functions properly in the symmetric multiprocessing architecture models of the computer. SMP is best for the games and other high graphics required areas as proper distribution of tasks are done by the processors that ultimately result in better quality of graphics at the time of execution. The places where multiple executions are made by the computer, in those areas SMP works best as there will be more processor working concurrently. Uni processor will work slowly and will not benefit the person while by using SMP the work will be completed in less time. (Rodrigo)

References

Multiprocessing System, Retrieved from, http://www.itswtech.org/Lec/Manal(system%20programming)/simeners_A/Multiprocessing_System_Cimenar.pdf

Irv Englander (2003), Chapter 11: Modern Computer Systems, Clusters and Networks, John Wiley and Sons, Retrieved from, http://www.google.com.pk/url?sa=t&rct=j&q=master%20slave%20multiprocessing%20architecture%20in%20terms%20of%20memory%20access&source=web&cd=3&cad=rja&ved=0CDsQFjAC&url=http%3A%2F%2Fwww.anvari.net%2FCOSC402%2Fch11.ppt&ei=Vc8LUeaeNMOYtAbFkoCwDQ&usg=AFQjCNEL0BiaJbLNhQbrxg3dIg61Wog7rw

Hyper-Threading, Retrieved from, http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Hyper-threading.html