This is really the reason why I have not bought Rift and have only played the storm legion beta and the trial. It's that my highend PC does not run Rift at a FPS that I would like. I get around 40 in almost every area and it's kind of annoying lol.
Also, the shadows in the game look horrible. I don't know if it's just my graphics card on rift or if it's the game. I run BF3 on ultra flawlessly and also GW2.
If anyone doesn't see my post at the bottom. My cpu is overclocked to 4.2ghz and my gpu is at 1225/1575