My server rack pulls 650W 24/7. That's 15.6 kW/day or 468 kW/month. At my current rate of $0.11/kW, that's $51.50/month. Id definitely look at your HVAC system. At my old place, my HVAC system was 30 years old and overcharged, so it rarely turned off, and my average bill was $400+/month. In my new place, the HVAC system is much more modern and bills hover around $230/month
Chatgpt is correct here if you use an Intel w-2400 CPU, which has 64 pcie gen5 lanes, but if you use an Intel w-3400 CPU you get 112 gen5 lanes. If you're just running pcie gen4, you might get more lanes but I'm not sure.
That said, if you're just looking to run your gpus at full bandwidth and don't need pcie gen5, you could go threadripper pro 3000 or 5000 series and a wrx80 motherboard for 128 pcie gen4 lanes.
Also the new threadripper and threadripper pro 7000 series is coming out on Nov21. Personally I'd get that over the Intel w-2400/3400 series.
I don't know how/don't have the tools to do it myself but if you call up an HVAC company they can come by and check the coolant levels. If it's too low or too high your system is going to be working overtime to maintain temps. That's what happened with mine. I set it to 68 but my cooled air output from the HVAC system was only 67. It needs to be lower or it'll take forever to cool down the house. After the coolant levels were fixed, the HVAC air dropped to 62F