Reducing ground bounce

True, true. In the tests we attempted, the pin locations that were tri-stated actually bonded to pads on the die which dispursed the SSOs at the the pad level. A no connect doesn't have any pad connection and thus probably won't help reduce SSN. The point of my post was that we found SSO is reduced by either a tri-stated pin next to the aggressors or a programmable GND. No real difference, at least on Stratix II.