Review: A Case for NOW (Network of Workstations) 
Author: Jesse Pool
Number: 994910968

Commodity, off-the-self computing components offer a higher cost-performance over custom designed systems (MPPs, mainframes, supercomputers). The challenge is to build large scale computing systems out of mass-produced components in order to achieve comparable performance at a fraction of the cost.

Anderson et al. do a good job in arguing that, at the time of publication, commodity computing components (RAM, bandwidth, etc.) had reached a point where they could be used to develop large scale computing systems. The paper presents a fair cost analysis highlighting the requirements for performance comparable to that of a MPP. Their research concludes that a scaleable network, a parallel file system and low communication overhead are the primary consideration for high performance in a NOW system. Inherent challenges in the model are also discussed, where I/O bottlenecks seem to dominate.

The primary weakness of this paper is its assertion that the operating system must be altered at the kernel level for NOWs to be successful. This is in direct conflict with the premise of the paper, which is to build MPP comparable performance on mass-produced components. Although it is obvious that integration software is required, the argument is weakened by this section of the paper. \

The incorporation of sociological considerations into this research paper is well thought out and thorough. I found that this section contributes a great deal to the use of the NOW system in practice.