With a high-end video card, you can up the resolution to the highest your monitor allows with almost no speed hit, and even maximum AA/AF levels will not affect frames much to the extent that you experience slowdowns because of a GPU bottleneck. Super 2xSAI is a software graphics filter that tries to smooth textures, and the other texture filter is a basic bilinear filter. You can either enable both, one or none depending on your preference. That's pretty much it for Jabo's plugin. Rice's Video allows the loading of external textures to replace existing textures in the game, and also has other texture filters to use.
PJ64 will mainly use your CPU to do most of the work emulating the N64's hardware, and the graphics card does little processing itself so has an easy time display the relatively simple graphics. Some budget graphics cards or certain types of onboard graphics can sometimes run into problems at certain quality settings, and below minimum spec cards will start to show graphical glitches. High-end systems will not run into these types of problems.
Most N64 games won't slow a high-end PC except some framebuffer effects, slowdowns that occurred on the real system, or some core/gfx problem with PJ64 that causes a certain game to be unavoidably slow on any system (as seen with Mystical Ninja and all plugins bar Rice's Video). Most of these problems are unavoidable. Copy framebuffer to RDRAM is pretty much the only configurable setting that can hurt performance on even a high-end machine in some games.
