QPI at over 4GHz?

Is this possible yet? I remember reading a while back when the i7 and X58 was new that the QPI simply can't go over 8GT/s or 4GHz due to physical limitations... is this still true today? Or has this little issue been overcome?

some chips can go over that, I think now the percentages are greater for those that do. In the end it is still luck of the draw