Increasing the clockspeed of TBMT3 is a bit of a mixed bag.
The availability and frequency upside of Intel® Turbo Boost Max Technology 3.0 depends upon a number of factors including, but not limited to, the following:
- Type of workload
- Number of active cores
- Estimated current consumption
- Estimated power consumption
- Processor temperature
You need a large amount of variables to be satisfied before you hit 5.4ghz or 5.6ghz
If those speeds are rarely maintained for very long I wouldn't expect a 5-10% in gains.
It's a very similar story with base clock speeds.
If the cpu is sitting near its base clock speed it probably is idle and not doing much work.
Eventually the cpu settles into a middle ground between those 2 extremes when doing work.