This empirical study investigates the architectural design process, focusing on the influence of computer-aided drawing (CAD) tools during the initial design stages. Given the increasing reliance on CAD tools in contemporary architectural practice, the primary objective is to assess quantitatively how CAD tool adoption affects design productivity. The research was conducted in two phases, utilizing the protocol analysis method. In the first phase, we introduced a novel approach by having third-year architecture students complete two design assignments: the first using traditional freehand sketches and the second employing CAD tools. This unique method allowed us to capture their design actions and thoughts using the Concurrent verbalization technique. In the second phase, a meticulous comparison of the two sets of design protocols was undertaken. The analysis yielded surprising and counterintuitive results. Contrary to common beliefs, the use of CAD tools during early design phases can lead to unintended outcomes. Despite their digital precision and convenience, these tools may inadvertently impede cognitive productivity. Designers employing CAD tools showed signs of hesitation and indecision, resulting in prolonged design timelines and diminished ideational productivity. These findings have profound implications for architectural education and practice. They underscore the necessity for a balanced approach to integrating CAD tools into design processes. Educators and professionals must carefully consider the potential impact of these tools on the creative process, prompting a reassessment of their role in architectural design curricula and workflows. Future research holds great promise in exploring strategies to optimize CAD tool usage to mitigate their disruptive effects on early-stage architectural design. Additionally, investigating the role of training and interface design in enhancing the synergy between designers and digital tools offers exciting and fruitful research directions. In summary, this study highlights the complex relationship between CAD tools and cognitive productivity in architectural design, prompting a reexamination of their role in shaping the design landscape.