OPENGL Screen Savers May Degrade Server Performance

• Microsoft Windows NT Workstation versions 3.5 and 3.51
• Microsoft Windows NT Server versions 3.5 and 3.51

SUMMARY

If OPENGL screen savers are used on a Windows NT 3.5x Server, network server performance (the Server's responsiveness to clients) may be degraded while the screen saver is running.

Performance degradation is due to the number of calculations and memory needed to produce the screen saver image. A decrease in performance of the computer has been observed on Windows NT servers with SQL Server and SNA Server installed. If a screen saver is needed, change it to a non-3D/OpenGL screen saver.

NOTE: This behavior has also been seen when using the Marquee screen saver with a very large point size set for the text (although the dialog box only shows numbers up to 72, the Marquee screen saver allows a point size of up to 200).

MORE INFORMATION

OPENGL screen savers use a great deal of CPU time because 3-Dimensional graphics are complex and require more computational time than the BitBlt graphics which standard screen savers use. Other services, such as the Server Service, must wait until the screen saver computations are complete or until the screen saver uses up its full CPU time slice. With a slower processor the performance degradation is more evident. For the fastest server response to network clients, use the Blank Screen screen saver.