According to the page here: https://www.humus.name/index.php?page=News&ID=228
The best way to draw a circle on a GPU is to start with a large triangle, and keep adding additional triangles on the edges until you've reached the point where you do not need to add any more triangles (smaller than a pixel)
I'd put money on that the best way is actually to draw a quad, or single triangle, and draw the circle as a SDF in the fragment shader