De-centralizing the VNC Model for Improved Performance on Wall-Sized, High-Resolution Tiled Displays
Daniel Stødle, John Markus Bjørndalen, Otto J. Anshus · 2007
This paper presents changes to the Virtual Network Computing (VNC) model to improve performance on wall-sized, high-resolution tiled displays. VNC does not fully utilize data distributed to the tiles, noticeably reducing interactive performance when panning images and moving windows. By de-centralizing the VNC model, the VNC viewers can exchange pixels amongst each other, improving performance. The VNC server changes from individually servicing viewer requests, to servicing the viewers once everyone has requested an update. The model is implemented, and its performance documented through experiments. When panning images, the number of pixels refreshed is increased three times or more, while reducing the server’s bandwidth by 74 % and CPU load by 35%. When moving windows, the number of pixels refreshed is increased by a factor of 1.8, while reducing the server’s bandwidth by 68 % and CPU load by 19.7%. The paper demonstrates how conceptually simple changes to VNC, while complex to realize, can yield significant performance improvements. 1