PCIe 3 Connector Layout

Many implementation guides recommend cutting back the layer 2 ground plane under the 28 mil connector fingers in order to make the fat finger look like a lower impedance by referencing a plane further down in the stack. If you have plenty of design margin, this is fine with me. If you are coming up with ghost errors or worse, this video will explain the side effects of that strategy and suggest an alternative strategy without the nasty side effects.