i made some testing yesterday with llc levels till lvl 7
here are the results

Frequency 4.5ghz
Vcore: 1.35v

llc enable idle 1.344 load 1.332
llc 1 idle 1.332. load 1.296
llc 2 idle 1.332 load 1.308
llc 3 idle 1.356 load 1.344
llc 4 idle 1.380 load 1.356
llc 5 idle 1.392 load 1.416
llc 6 idle 1.404 load 1.440
llc 7 idle 1.416 load 1.460

for me the best one was the lvl 3 cuz there is no overvolting and load the vdroop is less than the other options

best regards