If you mine on NiceHash consider using the string --diff 2 and mining Quark (Twice the speed for the same payout per GH as X11) they have a strangely high stratum difficulty after a few minutes, probably to deter single thread floating point submissions (quad core = 16 FP submissions) you will notice with --diff 2 string your speed will appear as 25%+ more than your actual hash power, I believe because it splits the difficulty by 2 between all threads so one thread isn't working on a 1,000,000,000 size share and another is doing 130,000 and waiting to submit, with GPU's this effects the memory usage and doubles the hash rate submission. This only seems to work with Quark that I know of since NeoScrypt and Lyrva2v2 just submitted a bunch of bad shares.