A little help!

All performance limiting reasons determine why the CPU had to reduce the clock from maximum to a lower state.
Max Turbo Limit means maximum fused n-Core turbo limit is causing frequency clipping (i.e. the turbo frequency has reach its maximum designed limit).
Turbo Attenuation means that when frequently transitioning between 1C and 2C (or higher core) turbo, the latter ratio limit will be used for both.