It depends on the sim, the one where I have my home in, if I have my draw distance to 120 and have shadows on, and I get about 10 fps. Without shadows, I get between 15 - 23 FPS depending on where I look. There might be something in the sim that is hogging the texture memory, since when I look in that direction with the lower frame rate, textures take longer to load. And after looking at the Statistics Window, there is not much giving obvious clues to what could be causing it.