damn shit is really bad, sky is failing, bubbles are bursting… any other clickbait I need to read up on before I go spend the last of the good days with my kid…?

coolest thing about us in the 50’s is that we’ve seen and read this shit many times before and don’t fall the “bubble du jour” or “shit’s really bad this time…” - especially readers here on HN, bubbles be bursting for yeeeears now, recession is coming, crashes are coming… genuinely am sitting here scared and shook about Buffet hoarding cash, that never happened before…

Any thoughts on Nix for this?

I used a large supermicro server chassis, a dual Xeon motherboard with 7 8 lane PCI Express slots, all the ram it would take (bought second hand), splitters, four massive powersupplies. I extended the server chassis with aluminum angle riveted onto the base. It could be rack mounted but I'd hate to be the person lifting it in. The 3090s were a mix, 10 of the same type (small, and with blower style fans on them) and 4 much larger ones that were kind of hard to accommodate (much wider and longer). I've linked to the splitter board manufacturer in another comment in this thread. That's the 'hard to get' component but once you have those and good cables to go with them the remaining setup problems are mostly power and heat management.

I've built a rig with 14 of them. NVLink is not 'an absolute must', it can be useful depending on the model and the application software you use and whether you're training or inferring.

The most important figure is the power consumed per token generated. You can optimize for that and get to a reasonably efficient system, or you can maximize token generation speed and end up with two times the power consumption for very little gain. You also will likely need to have a way to get rid of excess heat and all those fans get loud. I stuck the system in my garage, that made the noise much more manageable.

Every time I try to use NixOS I start off excited about all the benefits it can provide, but it always ends up frustrating me in some way and I'm reminded of why distributions exist in the first place. I don't want to have to dig into a config file for every little aspect of my OS to be in working order and then worry about having some hackey workaround when something has issues due to the lack of adherence to the FHS.

Greenlancer will draw up code-compliant plans that you can submit to your local building permit agency, and they'll revise if anything needs it. It cost less than $400 last year. You've done enough research that they'll be able to easily take your project and turn it into something legal.

I recently did an Enphase system of a similar size to yours. It was fully DIY except for wiring the combiner and a roofing company to plug all the holes I drilled. Working with PG&E was truly an epic year-plus battle culminating in a CPUC complaint, but in the end it was really just a bunch of emails.

I don't have any installer recommendations, but it should be easy enough to find a local electrician, and I've found that they tend to know others in adjacent fields.