Try the HiveOS community. There are several topics about tuning your vega's. I've used them alot on my Samsung Vega 64's.
Hi thanks for the reply, I have hynix memory Vega only and no matter which settings from other users I tried it always crash my hive OS forcing a reboot, I managed to go lower from what others gave me to try and I got to 43MH using phoenix miner, someone talked about strap 3 in another miner but haven't try that out yet