Computer hardware workstations

Molecular modelling used to be restricted to a small number of scientists who had access to the necessary computer hardware and software. Its practitioners wrote their own programs, managed their own computer systems and mended them when they broke down. Today s computer workstations are much more powerful than the mainframe computers of even a few years ago and can be purchased relatively cheaply. It is no longer necessary for the modeller to write computer programs as software can be obtained from commercial software companies and academic laboratories. Molecular modelling can now be performed in any laboratory or classroom. 

Products in Group 3 seem to us to represent the future of practical batch process control. In such systems, modern workstations perform the single-user functions (e.g control system design, set-up, and maintenance operator interface data collection historical reporting) for which they were designed, while powerful multitasking controllers perform actual control. As computer hardware and software standards continue to evolve toward distributed networks of processors optimized for specific kinds of tasks, such systems will, we feel, proliferate rapidly. 

In the area of computer hardware and operating systems the chemical/pharmaceutical industry increased its use of Digital Equipment Corporation (DEC) VAX computers with the VMS operating system, increased its use of IBM PC computers, and began to talk about more exotic workstations and parallel processors. 

CT and MR images are usually transferred to a computer workstation using internal network communication. Depending on computer hardware, images may undergo filtering for a reduction of unwanted... 

Previously not often used because very time consuming, nowadays VR, thanks to recent advances in computer hardware, has become a practical and interactive technique that allows processing and display to occur in real time (minimum 5-10 frames/s) at relatively inexpensive workstations. 

Different approaches in MM place different demands on hardware and software. The mix of supercomputers, personal computers or workstations, and distributed computing (grid and cloud) will be the choice of the future. Accordingly, the integration of platforms, visualization, user interfaces, and cross-platform visual programing tools are the need of the hour. 

The development over the past decade of efficient Monte Carlo algorithms for the SAW (Section 2.6) has combined with recent advances in computer hardware (notably clusters of high-speed RISC workstations) to make possible high-precision studies of SAWs that would have been unimaginable only a few years ago. For example, a recent study of SAWs nd=2 and J = 3 has employed chain lengths up to iV = 80 000, obtaining error bars of order 0.1-0.3%. (To be sure, this work took several years of CPU time )... 

Hardware the Revolution. Everyone agrees that a revolution is taking place in computer hardware. It is clear that we can, if we choose, have workstations on our desks in the 5-20 MIP range, at today s personal computer prices, in the next few years. Some moderately priced machines achieve the lower end of that scale today. But this revolution is not limited to raw cpu power. It extends to available memory, computer networking, hard disks, specialized processors, etc. 

Organic molecule calculations can be done routinely to good accuracy on workstation-class hardware. It is advisable to examine tabulations of results in order to choose a method with acceptable accuracy and computational time for the property of interest. The trend toward having microcomputer versions of computational chemistry codes is making calculations on small organic molecules even more readily accessible. 

Single processor calculations of nuclear shielding at the SCF level are limited by practical computation times in most hardware to about 800 basis functions with no symmetry or 1600 with high symmetry. Thus, the obvious solution of the problem is parallel processing using an array of inexpensive workstations or PCs. In a significant breakthrough, Peter Pulay et al. have implemented the first parallel computation of... 

Computational chemistry is accessible. Hardware has become far cheaper than it was even a few years ago, and powerful programs previously available only for expensive workstations have been adapted to run on relatively inexpensive personal computers. The actual use of a program is best explained by its manuals and by books written for a specific program, and the actual directions for setting up the various computations are not given here. Information on various programs is provided in Chapter 9. Read the book, get some programs and go out and do computational chemistry. 

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