Same issue here. It would run perfectly fine for the first 5 minutes or so, and drop considerably afterwards. I used to be able to run at 60+ FPS, but soon as the Wintersday Update hit, I’m usually at like 25. And, this is in semi empty zones with no other people around.
Also, nothing seems to effect it. I tried setting everything on low, but still getting the same exact results.
Edit: But, it’s NOT the CPU. If every single other game works perfectly, as did GW2 just minutes before the update, it’s GW2’s fault. Not my CPU’s. Yes, I’m sure there’s a certain setup I can use to make GW2 “work” normally, but I will not, and SHOULD not have to buy an entirely new CPU just because of a bug.
Again, GW2 worked fine pre update. Now, it doesn’t.