Will be joining the RX 56 Club later today. I expect to collect my Gigabyte RX 56 later and will post pictures thereafter.
Any decent guides for the whole undervolting / overclocing thing that a fellow like myself can understand?
Is it enough to raise the powerlimit to +50% and undervolt or do I have to manually mess with the P-states?
best and easiest way is get this tool - OverdriveNTool from here -
https://forums.guru3d.com/threads/overdriventool-tool-for-amd-gpus.416116/
Just set Power Target % to 50 and lower the mv of S6 and S7 to say S6 1000mv and S7 1050mv you also must lower the mv for the memory HBM to be the same as the lowest value you set in either S6 or S7. You don't need to play around with frequencies in S6 or S7 states UNLESS you want to start overclocking the card then you will have to start a process that can be a little tedious to determine which voltage is stable with the increased overclocked frequency of primarily your S7 state.
The first mentioned procedure of just lowering your mv for HBM memory first,remember this value must be set as low as you intend to set your lowest S states eg; HBM mv = 900 - S6 = 900mv (stock frequency) - S7 = 950mv (stock frequency), this is the easiest method to undervolt and achieve increased performance because each undervolted state with stock frequencies will be stable....it's only when you start increasing the frequencies that you will incur instability if the voltages are incorrect.
So try HBM 900mv - S6 900mv - S7 950mv = check frequency by running Superposition or Heaven or 3DMark stress test
HBM 950mv - S6 950mv - S7 1000mv = check frequency etc
HBM 1000mv S6 1000mv - S7 1050mv = check frequency etc.
Can also use HBM 950mv - S6 975mv - S7 1025mv = check frequency.
Each voltage change will affect frequency. Hope this is all clear and helps.
OH, and you can SAVE oc profiles with OverdriveNTool as well which is a GREAT bonus.