How much is your electricity? I currently run 12 GPUs in my garage pretty much non-stop. 4 GPUs per machine, 3 machines. Each machine is about 1.2KW on average (I can tell because each machine is connected through its own rack UPS), or 13.2 cents per hour, or $95/mo. Which, IMO, is not bad at all. That's less than $300 per month for 12 GPUs.
