Memory DOES make a difference on equihash - though not a big one on the 1080 ti.

 On my Aorus (not the extreme), I found that +100 core +100 memory was the best setting for speed/efficiency that was stable - +150 memory gave a few more sol/s but wasn't long-term stable as those cards seem to push the memory pretty hard already, +200 memory gave me LOWER sol/s probably because it pushed the card up into the next "strap" range with higher latency settings.

 50% TDP (125 watts) gave 505 hash - don't bother this is a waste of the card.
 60% TDP (150 watts) gave 620 hash - this seems to be the best efficiency point that still has decent hashrate.
 70% TDP (175 watts) gave 680 hash - efficiency dropping but not a LOT yet
 80% TDP (200 watts) gave 725 hash - efficiency dropoff getting noticeable
 90% TDP (225 watts) gave 760 hash - ditto
100% TDP (250 watts) gave 780 hash - waste of power unless you have VERY VERY cheap power, and even then it's a bit iffy - though the cards still runs pretty cool at this setting as long as it's NOT in a hot room.


 Other cards may vary, though all of the cards I have to date (1 Gigabyte Windforce, 1 EVGA SC, pair of Aorus) all seem to match nearly identically up to about the 80% point, then the EVGA and Windforce start dropping a bit as temp doesn't let them boost the core as much.