This is by far the best settings I tired.
4x Vega 64 with waterblocks.
Core
1300@0.950V and
1100@0.95V Normally it was 19.24kH/s/Vega. After the timing set is about 21.85kH/s/Vega.
Max temps: Core 40*C, HBM mem 53*C.
Team Red Miner v0.4.3 L22+22. HWinfo GPU chip power 157W. I don't have a power meter.
almost 4h no errors.
https://ibb.co/R7CWKjwvega64 lc is happily mining 21.2kh/s with 1230/1090@800mv showing only 115 watt in HWinfo GPU chip power