ram helps a ton.
when i had 512mb ram stock i couldint even play on mem smooth.
i went too one place and it did went down too 20fps but most of the time its 25fps and up too 60.
and inside is around 30fps too 60fps.
right now i tried 1600x1080 and with 2xanti and no hdr and the frames are 20 too 30fps inside and around 20fps too 15fps outside and when i turn the grass we down so you cant see it, its20fps and up too 30fps outside.
what settings you runing it at?