Parallel Computing
          An Introduction into Hardware and Software

                           Thomas Ludwig

Many interesting problems in science and technology require massive
computational power to investigate them. Gene analysis, weather
prediction, and wind tunnel simulations are popular examples. High
performance computing facilities are located in computing centers of
universities and research laboratories and are not as easily
accessible and usable as workstations. The concepts of how to use them
efficiently are therefore not common knowledge.

This lecture will give an introduction into programming for high
performance. We will at first look at the hardware aspects of modern
supercomputers and classify their architectural
characteristics. Basically we can distinguish these machines into
shared memory and distributed memory architectures. However, with
modern systems we find also hybrid approaches, where computers of
different archtiectural concepts are joint together to form a super
computer of high computational power. Aspects of network technology
and I/O-facilities play a crucial role in the overall concept.

Second, paradigms of parallel programming will be discussed. The
concrete way to bring a program to a parallel computer depends on the
architecture of the machine, the structure of the problem, and the
programming concept chosen. Usually, the first two factors are fixed
and we are free to select our favorite programming concept in
dependence of both of them. Therefore, we will discuss programming
concepts in detail. We can distinguish message passing based
programming, shared memory based programming and the data-parallel
programming model. The lecture will give an introduction into these
and compare their applicability.

The lecture is oriented towards computer scientists and researchers in
applied sciences who want to introduce high performance computing to
their field. The presented material is also a good starting point for
those who are interested in architectural aspects of parallel hardware
and in aspects of parallel programming.