I have not in truth really bothered to compare frame rates...
All I know, is that I run a game on my fastest PC and I run that same game on my slowest PC, and the difference is too small for me to seriously worry about...
Sure, I suppose, if I was to put them head to head, side by side, or run frame-rate benchmarks, I will see a difference, but to just go to any one PC and start playing a game, is pretty much exactly the same experience as it is to play it on another PC.
I do however, say this with a hidden pinch of salt, because my slowest PC is actually a single core AMD 3700 and my fastest is a Quad core C2D Q9450 so there is a massive difference there, but of course I did say "These days" and I stick by that... The Q9450 is no different to the Q6600 or even the E6300 in nearly all the games I play, and bar a few % here and there, I really cannot see THAT much difference at all...