The whole point of a screen saver is to display an graphic that is not static so that an image will not “burn-in” to the phosphor display of a computer monitor. That isn’t a concern with modern monitors as they differ from the CRT screens of olde. Still, screen savers continue to display dynamic images today.
If you want something that is less dynamic, try using a screen saver that pulls images from a favorite photo album, or one that displays only a simple text & time that slowly moves about the screen. These will require less processing power than other full color dynamic images.
Or, better yet, just set the display to turn off after a short period of inactivity.