-i 0 also fastest for me, -i 1 and -i 2 have 100% cpu

r9 290 ref stilt bios  1100/1250 +19mv - 65 +/- 5sol
2x r9 290x xfx stilt bios 1100/1250 +25mv - 65 +/- 5sol
2x rx 480 nitro+ silentnitro bios 1150/2080 - 60 +/- 5sol


total - 385-405sol

celeron g1840 + 16gb ram 128gb m2 ssd

any way to get better speeds with this g1840?