High CPU load from image slideshow screensaver

[Adam Rosi-Kessel <adam rosi-kessel org>]

The image slideshow screensaver in gnome-screensaver puts such a load on
my laptop's CPU that the fan runs constantly and tasks such as music
playing with totem become very choppy. Although it's an older laptop, I
would hope it wouldn't be viewed as totally obsolete: it's a Pentium III
700 MHz with 512M RAM.

The only way I can get music to play smoothly while the screensaver is
on is to renice -1 the music task and +20 the screensaver task.

Is there some reason the photo slideshow is so CPU intensive? At first I
thought it was because it was resizing the images to fit the screen, but
after converting all the images in my image directory to 1024x768 (the
LCD resolution), the result is identical.

Can anyone suggest a workaround for this? It doesn't seem like too much
to ask for to be able to play normal bitrate MP3s and have the
screensaver on at the same time.

I'm using Debian Etch.