With just 10 pieces of 3090s you are already at 1GH on the Ethash algorithm, why aren't people doing this instead of having so many GPUs around, taking so much space and having to use more risers and more motherboard, why are people not going this way?.
Very high price. Even if I needed a closed case, I would have assembled it myself from analogues no more than $ 650. But if they calculate the cost of PTX 3090 video cards, then for a similar price you can get a larger hashrate.