best simple antialiasing of lines -- textures or alpha vertices?

Hello,

I have read that a good way to antialias lines in openGl is to use a texture map of an antialiased circle and map the coordinates of a rectangular set of vertices to it, like this:

However, I’ve also read about adding a layer of polygons around the outside of a rectangle, with the outer vertex alpha equal to 0. That is what I do now, and it looks fine.

But I am wondering if the other way is faster, maybe? Which technique is better?

Thanks
Bob

Given that the same number of pixels are rendered the few the number of triangles is better.