I have a 13700k that is undervolted (-0.15) on an Asus B660-i motherboard along with DDR5 6200 ram. CPU is cooled by a 280mm AIO. I can hit 30K and 2K scores in Cinebench R23, multi and single respectively.

My question is around the Max Turbo Boost of 5.4 Ghz. Seems like at idle, gaming, watching youtube, or benchmarks I only sustain 5.3 Ghz. For a short few seconds it might jump up to 5.4 Ghz during the multi core R23 benchmark. No change in behavior with Multi Core enhancement and Adaptive Boost on or off. Is my motherboard the limiting factor? If so, would a z690 or z790 enable a more consistent/sustained 5.4 Ghz performance or is the very brief boosts up to 5.4 Ghz normal?