Simple Realism is a Minecraft modpack with Patrix 32x and Round Trees listed among its packs. For a better experience, the author recommends the PRO version of Physics Mod. This is a recommendation rather than a stated installation requirement.
When setting up Simple Realism, allocate 6–8 GB of RAM, as recommended by the author for better performance. To make installation easier, use one of the suggested launchers: Prism or ATLauncher.