Guild Wars 2

How its possible that one time/day i had 60 fps and another 130 fps in gw 2 ?

Example:
Today at the morning I turn on the game (instaled halloween patch) I play for a while with 120/130 fps in game. After school (about 6 hours later) I turn on gw one more time (another patch) and bum! 60 fps.

I dont understand that and it isnt a single time when i have this problem. Anyone have similar ?

Its same on standard HDD. I saw even this loading delay on cutscenes when you talk with npc (face to face) in hero story quests (talk shows up after 2-4 sec in compare with “before patch”). Same on creating character when you wanna choose profession.