Uncheck texture filtering first unless you have a tiled texture that gets moire in the distance. See how that one goes. Given the size of the file already, and the size of the image being rendered, it is possible that the whole of it may exceed your available memory space.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)