Performance

Enable transparency effects

Draw selections and other special graphics using transparency effects. Disable the option to draw them using outline or opaque fill styles and increase speed on selections.

Memory Usage

Okular can achieve best performance by tuning the memory usage, based on your system and your tastes. The more memory you let it to use, the faster the program will behave. The Default profile is good for every system, but you can prevent Okular from using more memory than necessary by selecting the Low profile, or let it get the most out of your system using Aggressive. Use Greedy profile to preload all pages without risk of system memory overfull (only 50% of total memory or free memory will be used).

Rendering

Using this group of options you can improve text and image rendering in Okular. The result depends on the device to display the document. Enable Text Antialias and Enable Graphics Antialias items can be used to switch on and off spatial anti-aliasing of text and images in document, correspondingly. Enable Text Hinting item is meant to be a switcher for font hinting. Antialiasing and hinting change how the documents are displayed, you may want to tweak them to your preference.