It seems that the graphics being produced take an inordinate amount of CPU
time. If the screensaver settings are changed so that the screen goes blank,
the processing speed doubles.
To change the setting. Go to the display properties page. You can get there
by right-clicking on the blank desktop and selecting Properties. There is a
tab there specifically for screen savers. Make sure that SETI@Home is the
screensaver selected and then click the Settings button. There is a check
mark there for 'Go to blank screen'. Add that check mark. It is off by
default. Set the minutes to some value. Less is better but you won't see the
client running when the screen is blank.
I have seven machines running the client as a screen saver. The average was
over 50 hours before the settings change. Now it is under 30 hours.