After some evening testing last night, till very late 3am! I was slowly approaching the limit for a level 5 (lowest setting) for the LLC with the auto voltage set for 4.9ghz on the Pcore. I set the lowest possible LLC at level 5 with the auto voltage setting 1.31/1.32v for 4.9ghz it drops the voltage down to 1.28v during R23 bench. The temps are good and stable with plenty of headroom.
Ecore is set to the limit for this overclock to 4.0ghz, any higher and R23 will crash when you start the benchmark.
Ring Ratio is set to 4.1ghz, though from 4.0 to 4.1ghz it did nothing to R23 score.
The problem now lies with setting the pcore ratio to 5.0ghz as the auto voltage will automatically jump to 1.34/1.35v, though this technically is well within the 1.4v safe limit that i've been reading about, it pushes the temps to around 90c on a custom loop and does require LLC level 4 at a minimum though i've had better results with Level 3 which pushes the temperatures even higher.
I'm thinking at this point whether its just worth sticking to 4.9ghz pcore and 4.0ghz ecore or push it to 5.0ghz pcore and 4.1ghz ecore and deal with the temps as this temp is only during R23 bench, during normal gaming it will happily sit around 60/65c depending on the game.
4.9ghz pcore
4.0ghz ecore
4.1ghz ring ratio
-------------------------------------------------------------------------------------------------------------------
Edit: here's the run with
5.0ghz pcore
4.0ghz ecore
4.1ghz ring ratio.
Max average temp 94c! Ouch! Vrm temps sitting at 85c. Really have hit the limit here, but im still unsure how to use the voltage offset as it works in mv which means setting something like -100 should be -100mv but im getting crashes during post and windows and -100 seems to be the limit too.
-------------------------------------------------------------------------------------------------------------------
Edit 2: Here's the final run
5ghz Pcore
4.1ghz Ecore
4.1ghz Ring ratio
VID Voltage 1.35v and Vcore voltage 1.328v with temps average 94c again
It's an improvement but barely!