There was a thread on reddit discussing the game graphic settings that I’m unable to find right now. It listed which settings were safe to max out without dropping FPS and which not. In addition to setting character models and numbers to low, turn off all reflections and post-processing. IIRC you could have shadows maxed but shaders low. Really don’t remember the rest of the post, sorry.
All GW2 maps have a water “base” and supposedly the game will render reflections for it even if there is no water actually shown.
https://www.reddit.com/r/Guildwars2/comments/2tqf66/guild_wars_2_performance_guide_how_to_get_the/