I own Sapphire RX vega 56(hynix) and I am trying to tweak it without success.

I BIOS flashed it to Sapphire.RXVega64.8192.180125_1. Did I use the correct BIOS mod? I read somewhere that _1 at the end of the name means that this is NOT a power saver bios.

Then I was looking for the best MEM and CORE first. But I saw that people use 1080 Mem and more. I get errors with 1020 and above(dots on the screen) and I have to restart the PC.
I was able to get 40MH/s on ethereum with the following settings:
Core
P7: 1530/1000
Memory
P3: 1000/950
Timing level 3

So my questions are:
- What timings should be lowered/raised in order to get better speeds?
- Did I use the correct BIOS to flash the card?
- what Core and Memory should I be using?
- what does the Timing level mean exactly?
- is there any difference between AMDtweaktool and BIOS editor except that AMDtweaktook does not require a restart/loading BIOS everytime?

Maybe on the side note-is it better to do the timings in BIOS editor or in AMDtweaktool for RX570 4gb?

I own mostly Nvidia an RX 5704gb so this is all new for me.
Any help much appreciated!