I was having severe issues as well, and I also have an overly powerful computer. Except mine is all AMD/ATI products. I was really stumped, all other games I have on Steam work just fine, but GW2 puts my 16gigs of Ram, AMD 6870, 3.4Ghz Phenom x4 to the test. After fussing with the setting both in the game and the console, I couldn’t get anything over 35-40 FPS, with a 10-45 FPS range. It really struggled when I would hold A or D and spin in place. I went into my Catalyst Control Center for AMD/ATI products, and turned up my lowest setting on both my CPU and GPU. I forced both to always work at a minimum of 80% Went back into the game, messed with the setting once more, and voila, smooth gameplay and very minor lag. I also used a program called Speedfan on my other screen to monitor my computers temperature, so as to not overwork it accidentally.