these are my settings that i have set for my preset. i would recommend you crank the power limit all the way up, start out with +120-130 on the core clock and run a benchmark, i like valley benchmark and furmark, i use furmark first and run it max for about 5 minutes, if no crashes then i crank up the core clock by another 10 and repete till it crashes within 5 minutes of use. then i turn the core clock down by -5 and run it for 10 minutes, if it doesnt crash then i run valley benchmark for around 20-30 minutes and just leave it at that if i dont get any crashes. i usually dont bother much with the memory.
https://gyazo.com/b55892988b6a823c634473d851304ab0