I'd disagree - but I'm talking about the difference between a 1Ghz clock and a 5Ghz clock - it's always going to matter at the cutting edge - if the clocks are

I'd disagree - but I'm talking about the difference between a 1Ghz clock and a 5Ghz clock - it's always going to matter at the cutting edge - if the clocks are equal then what you're trading off is pipeline depth - which effects all sorts of stuff like the cost of mispredicted branches (and as a result the sizes and complexity of branch predictors)