asimov
From my observation, the average annual raise is ~2.5-3.5% at the same role. The spread between top and average performer is minimal. There isn't much of a bump on base salary due to promotion. The bump comes in the format of higher bonus eligibility.
The problem lies in the corporate budgeting for compensation. My department gets an automatic budget that equals about 3% of total payroll and then it is my responsibility to allocate it, so i can grant someone 5% (I believe they do limit me at 5 or 6%) but then I would have to give others a 1% or 2% raise. One year, I have over-allocated because the system let me do it but i think it got reversed somehow. Ultimately one person had to stand out quite a bit and another to suck quite a bit to warrant this raise, so it is ultimately impossible in corporate america to get a raise unless it is a promotion (even in that case, many companies have a rule that a promotion raise may not be more than 10% or 20%). Leaving the only other option - job hopping.