LOL if you pack 1660ti together they ain't cool no more and you can add the trouble of managing 4 pieces of them.
go for 3090..what is this bull market for?
My 3090's rarely see 60c.. That's air cooled wtih a fan...
So it takes 6 cards to pull in 186MH/s vs 1 x 3090 tuned can bring in 120MH/s... I'll stick with the single 3090's (although I have many more) in this scenario...
Not to mention the 1660 has a 100% power draw of 120W.... The 3090 draws 350w-375W....
88-92% power (311 - 322w per card) with a +1020 mhz bump on the memory clock and that's it for 120MH/s. 8 GPU Open Air Racks with Fan's behind, custom fan ramp up in afterburner and a box fan over the top. That's all it takes.