Most windowing systems follow the independent overlapping windowsapproach, which emerged as an answer to the needs of the 1980s' technology. Due to advances in computers and display technology, and increased information needs, modern uses demand more functionality from window management systems. We proposed Elastic window with improved spatial layout and rapid multi-window operations as an alternative to current window management strategies for efficient personal role management [kandogan]. In this approach, multi-window operations are achieved by issuing operations on window groups hierarchically organized in a space-filling tiledlayout. Thispaper describes the Elastic Windows interface briefly and thepresents a study comparing user performance with Elastic Windows and traditionalwindow management tewindow situations. Elastic Windows users had statisticallysignificantly faster performance for all 6 and 12 window situations, for task environment setup, task environment switching, and taskexecution. These results suggest promising possibilities for multiple window operations and hierarchicalnesting, which can be applied tothe next generation of tiled as well as overlapped window managers.