Without packet coalescing, small IP packets, such as those generated from user input events, cut the modem throughput dramatically by increasing the overhead to packet size ratio substantially. Together with the small packet problem, communications errors further decrease the usable badwidth and increase latency. Adding local fonts to the system could substantially increase display performance, but doing so would require adding a network file system to the mobile computer's operating system. Pixmaps are currently stored on the wired network and transmitted as needed to the mobile computer. Moving pixmaps to the mobile host may speed display performance, but it would require the server to remotely manage memory and painting into pixmaps would become slower.
Problems also arise in maintaining local applications alongside remotely managed applications.
X was designed for continuous connection to a single workstation for the duration of a session. This can be achieved without any changes to applications by providing an additional layer of indirection to the X system. In the pseudoserver model, a wired-network computer is seen to all X clients as the X server. This pseudoserver is seen to all mobile X servers as a single X client. This model permits the pseudoserver to be solely responsible for maintaining connections with various X servers and allows the possibility of mapping a single session to mobile users with different hardware capabilities.