Aida64 latencies improve with CPU speed. I don't think it matters if it's PE 3 or PE4, but the actual CPU speed. Which in your case is increasing as you switch from PE 3 to PE 4. If you adjust your multiplier while your booted with PE 4 to match your PE 3 you will most likely find it's the same latencies. I've played with it quite a bit.Just wanted to give an little info on our PE level 3 and 4 as there seems to be some confusion on what it is doing. While yes it does increase the duration of how long the boost can hold...the biggest change takes place in the CPU MSR registers. Whatever The_Stilt was able to do does change how the CPU on die caches work. Somehow it speeds the L1, L2, and L3 cache up in terms of reducing latency.
The first screen shot is with PE Level 3 and the second screenshot is PE Level 4 Notice all latency improve some by good margin. However the boost level is the same with either PE level.