Performance analysis of a dual processor workstation

Performance of personal computers has been increasing steadily since their introduction in the early eighties. Personal computers available today employ technologies that were not long ago exclusively used on super computers and main-frames. One of the most recent developments in the personal computer technology is the usage of multiprocessors in order to increase the computing power. However, since it is known that computing power increase is not directly proportional to the number of processors, the performance increase gained from additional processors is difficult to predict. Many researchers claim that personal computer technology, based on Intel x86 design, has scaling problems when multiple processors are used. Computer manufacturers so far have failed to provide reliable information related to scaling problems. In order to analyze the performance gain from an additional processor in a personal computer and to study the performance dependence of the computer architecture on the operating system, a dual processor computer system was designed and built from the functional blocks available on the market. The fast Fourier transform algorithm was adopted and modified, to be used as the computation intensive performance indicator. The FFT algorithm was run on the designed two-processor system under Windows NT Workstation version 4.0, and Linux version 2.0 with and without the use of the threading techniques and the performance gain due to the second processor was determined. It was observed that the addition of the second processor resulted in the maximum speedup of 1.91 under Windows NT and 1.67 under Linux, when the threading techniques were used. Furthermore it was observed that without the use of the threading, the addition of the second processor, under specific conditions, impaired the system´s performance. The paper presents the details of the performance study.