Comparing and Contrasting PCs and mainframes Essay Example for Free

Comparing and Contrasting PCs and mainframes Essay Before the existence of personal computer or PC, there is minicomputer or microcomputer, the term â€Å"computer† simply referred to mainframes. Mainframes and personal computers have changed drastically over the years but their core functions and systems have stayed the same. The mainframe is used to connect multiple users for large organizations, while personal computers are generally used for a single user. The more drastic changes for mainframes and personal computers have been the increase of speed, memory, and the reduction of size. Mainframes use to be the size of buildings, now they are the size of a normal Intel blade server system. Last time when you need to access the mainframe you need to use a terminal for data entry or retrieve certain data. Then, the idea came to off load some of the processing from the mainframe and place it on a personal computer. Compare A mainframe is not much difference from a personal computer. There are many similarities between mainframes and personal computers which stands to reason since one evolved from the other. Both mainframes and personal computers have one or more central processor units, a huge number of memory, one or more busses, and one or more I/O systems. Another similarity between the two is that they are both IBM-based systems and similar hardware is used to build them. They can also perform some complex calculations, applications and handle multiple programs. Another area is that both require operating system to work and also to handle and optimize all the I/O systems or modules. Differences Although they are much similarity between the mainframes and computer as mention above, the similarity stop there as they are many differences too. Mainframes cost much more in terms of thousands of dollar than a normal personal computer or server. The mainframe nowadays takes up less space and less power consumption compare to a server farm task to do the same job. As mention (Shurkin, 1996), Transaction processing jobs run constantly in real-time and must be available more than 99. 99% of the time. The reboots and lock-ups common with PCs are simply not acceptable. Thousands of individual users can log in simultaneously from a variety of sources such as computer terminals, ATM, or Internet web sites, and complete a single transaction. Time-sharing jobs can be started when needed from a computer terminal by authorized users who then use the mainframe as their own big PC. Finally, batch jobs are started automatically by the system at regular times according to a strict predetermined schedule. Batch jobs are used to do the periodic processing required on the data being received from transaction and time-sharing jobs. Closing the accounting books at month-end or copying disk files to tape for backup are examples of batch type processing. The OS or Operating System in a mainframe such as from IBM z/OS which is the successor to the IBM OS/390 can run Multiple Virtual Systems (MVS). The new IBM z/OS support WebSphere ® Application Server on z/OS, and also the new zFS (System z File System) Direct I/O capability in z/OS. This help to enhance performance improvements to the system, and also provide an easier Parallel Sysplex functionality (IBM, September 2011). In an article by (Barnett G, 2010) stated that the mainframe is best suited for enterprise cloud computing as it is easily able to handle hundreds of complex applications or programs, and most important able to run hundreds of environment in a single physical footprint and easily deliver the 247 availability that our customers demand. Conclusion (Doerbecker Patterson, 2002), stated that the role of the mainframe has gradually changed from that of a data processor to that of a server, with the processing being done on the users PC. It has also been modified to interface to the Internet through the addition of TCP/IP protocols, Unix, and Java programming, to enable businesses to connect to their customers over that network. Once the only form of business computer available, the mainframe has survived the PC revolution and maintained an important function in commercial computing.