How Much is Performance Worth to Users?

In computer systems design, computer architects can evaluate features and techniques in terms of traditional design metrics like power, performance, and area but not in terms of net benefit or cost to the end user. For example, a security feature may come at a 10% cost to performance, but is this worth the tradeoff? The problem is that user-level features like security, privacy, and usability can be converted into a monetary amount but traditional architecture metrics (which lack the notion of user value) cannot. In this paper, we make the first known attempt to bridge this gap: We conduct two studies (one of which is incentive compatible) that elicit the value of performance in terms of US$ to end users. Thus in this work, we make the first known quantitative measurement of the tradeoff between performance and user value, providing architects with a novel design metric and filling a crucial gap in the end-to-end quantitative evaluation of systems.