Since you cannot in real-world set the same system for these two combinations, it is hard to show you the results.
514mhz x7 would be a 1:1, as I doubt your HZ's can do 1285mhz, to keep a 4:5 ratio. Even then..you would want to compare the NB speed and its affect on performance, so the only way to simulate that would be to use a e6700..like mine
and set the same clocks and such as your setup...only my cpu would lower the multi 3x to match your FSB,DDR and CPU speed.
Assuming we could run the same benchies is a 'controlled setup', our tests should show the NB's affect on the performance of system.
Im game..but my I dont get my SuperTalent ddr 800 until friday afternoon..so any test for now, will have to be done between 800-915mhz..[ocz is ok i guess