@Herewegoagain
Well... both yes and no.
Motorola provides Apple with 7455s that are overclocked, otherwise they only scale to 1Ghz. Or to put it in anoter way the current 7455s provided to Apple are overclocked by 42% (mac fans deny this claiming that the CPUs have been alterd for higher clockspeeds, I call this making adjustment so that the CPU dosen't fry when you overclock it).
Now what happens if you overclock a 7457 by 42% ,assuming that the 7455 and 7457 can be "equally overclocked", you get a proc running at 1.84Ghz overclock it by 25% and you get 1.6 Ghz. And last of all lets not forget that the 7457 has got 100% larger L2 cache then the 7455 (and the 7451 for that matter).
