My 4 slaves are capped at 15 FPS each, my main is capped at 30 FPS. I get 30 FPS on my main almost anywhere in the world, when I remove the cap, it goes to anywhere between 30 and 45 FPS. In cities it's a whole different game though, in Shattrah I get around 12 FPS on the main if I'm lucky.

Running on a AMD 64 3600+ X2 (that's a 2.0 gHz dualcore), 3.5GB ram and a Geforce 9800GT.