not sure why my 5080 is bottlenecking

just built a new pc with an i9 14900k and a RTX5080, my cpu tends to thermal throttle up to 100 celsius, i removed the aio pump and reapplied thermal paste thinking that was the issue, ive also tried undervolting down to 51 on all cores and it seems like lower temps idle but in benchmark it still throttles up to 100, however in the benchmark results its says my gpu is whats holding me back which i dont understand because i have a 5080