for the moment i'm installing windows 10 again,
The MOBO is an R2.0 pro btc asrock and i'm trying out 4 gpu 's
what would you mean with enable 4G decoding/mining mode?
when the windows is installed i'm already going to give it a try with the 17.12.1 driver, the timing straps should normaly be already set from 1500 to the 2000, going to try out the clock at 1150 cclock, 2100 mclock, 950 mvddc.
ASRock H81 Pro BTC doesn't have the 4G decoding option, you can skip it.
Start with 1950-2000 memory clock and 900-925 memory voltage, add gradually memclock and decrease voltage, checking memory errors through HWInfo64.