Depending on what version you have, getting to the screensaver setting may vary slightly. Under debian, which is probably 'standard' or close to it, its 'desktop > settings' whereas under SuSE 10.3 and its unified menu settings, its 'menu > control centre'. I don't have a SuSE 10, if that's what you mean (or Slack 10 for that matter), but I'm sure that you can find it, if it turns out to be different from those.
Control centre > screensaver gives you the screensaver settings.
If you never activate the screensaver, that should do what you want, so unselect 'activate screenserver when system idle'.
Note that powersaving, in the sense of running the cpu more slowly under light loads (e.g., AMD powernow), as seemed originally to be the question, is quite unrelated to this setting.